Tissue removal device with adjustable delivery sleeve for neurosurgical and spinal surgery applications

ABSTRACT

A tissue cutting device that is especially suited for neurosurgical applications is disclosed and described. The device includes a handpiece and an outer cannula in which a reciprocating inner cannula is disposed. A delivery sleeve may be selectively provided that is configured to be disposed about the outer cannula for delivery of a variety of devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.12/475,258 filed on May 29, 2009, which is a continuation-in-part of12/435,724, filed on May 5, 2009, which is a continuation-in-part ofU.S. application Ser. No. 12/404,407, filed on Mar. 16, 2009, which is acontinuation-in-part of U.S. application Ser. No. 12/391,579, filed onFeb. 24, 2009, which is a continuation-in-part of U.S. application Ser.No. 12/389,447, filed on Feb. 20, 2009, which is a continuation-in-partof U.S. application Ser. No. 12/336,054, filed Dec. 16, 2008 and U.S.application Ser. No. 12/336,086, filed Dec. 16, 2008, each of which ishereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to tissue cutting devices, in particular,tissue cutting devices that that include a delivery sleeve and which aresuited for neurosurgical and spinal surgical procedures.

BACKGROUND

Various abnormalities of the neurological system, such as brain andspinal tumors, cysts, lesions, or neural hematomas, can cause severehealth risks to patients afflicted by them, including deterioration inmotor skills, nausea or vomiting, memory or communication problems,behavioral changes, headaches, or seizures. In certain cases, resectionof abnormal tissue masses is required. However, given the complexity andimportance of the neurological system, such neurosurgical procedures areextremely delicate and must be executed with great precision and care.Some known tissue cutting systems lack the ability to deliver fluids andancillary devices to or near a surgical site. Other known systems lackthe ability to accurately and effectively adjust the fluid deliverylocation relative to the tissue cutting location. In addition, it issometimes desirable to operate a tissue cutting device as an aspirationwand. Many systems are unable to operate in such a mode or are unable toaccurately control adjust the extent of aspiration with precision. Thus,a need has arisen for a tissue cutting system that addresses theforegoing issues.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described by way ofexample in greater detail with reference to the attached figures, inwhich:

FIG. 1 is a perspective view of a tissue cutting device including afluid supply sleeve in accordance with a first embodiment;

FIG. 2 is a cross-sectional view of the tissue cutting device of FIG. 1depicting an inner cannula in a first relative position with respect toan outer cannula in which the inner cannula's distal end is locatedproximally of the outer cannula's distal end;

FIG. 3 is a cross-sectional view of the tissue cutting device of FIG. 1depicting the inner cannula in a second relative position with respectto the outer cannula in which the inner cannula's distal end is locatedat the distal end of the outer cannula;

FIG. 4 is a partial cross-sectional view of the tissue cutting device ofFIG. 1 in a first configuration in which a device-mounted tissuecollector is disconnected from a tissue cutting device housing;

FIG. 5 is a partial cross-sectional view of the tissue cutting device ofFIG. 4 in a second configuration in which the device-mounted tissuecollector is connected to the tissue cutting device housing;

FIG. 6 is a partial cross-sectional view of an alternate embodiment ofthe tissue cutting device of FIG. 1 in a first configuration in whichthe device-mounted collector is disconnected from the tissue cuttingdevice;

FIG. 7 is partial cross-sectional view of the tissue cutting device ofFIG. 6 in a second configuration in which the device-mounted tissuecollector is connected to the tissue cutting device;

FIG. 8 is a broken side elevation view of the outer cannula of thetissue cutting device of FIG. 1;

FIG. 9 is a broken side elevation view of the inner cannula of thetissue cutting device of FIG. 1;

FIG. 10 is a top plan view of a portion of the outer cannula of thetissue cutting device of FIG. 1 with the inner cannula removed from theouter cannula;

FIG. 11 is a top plan view of a portion of the inner cannula of thetissue cutting device of FIG. 1;

FIG. 12 is a top plan view of a portion of the outer cannula and innercannula of FIG. 1 depicting the inner cannula inserted into the outercannula;

FIG. 13 is a partial cross-sectional view of a distal region of theouter cannula and the inner cannula of the tissue cutting device of FIG.1, depicting the inner cannula in a first relative position with respectto the outer cannula;

FIG. 14 is a partial cross-sectional view of a distal region of theouter cannula and the inner cannula of the tissue cutting device of FIG.1, depicting the inner cannula in a second relative position withrespect to the outer cannula;

FIG. 15 is an exploded assembly view of the tissue cutting device ofFIG. 1;

FIG. 16 a is a side elevation view of a cam of the tissue cutting deviceof FIG. 1;

FIG. 16 b is an end elevation view of the cam of FIG. 16 a;

FIG. 17 a is a perspective view of a cam transfer mechanism of thetissue cutting device of FIG. 1;

FIG. 17 b is a perspective view of a cam follower of the tissue cuttingdevice of FIG. 1;

FIG. 18 is a partial perspective view of a portion of the tissue cuttingdevice of FIG. 1 with an upper shell of an outer sleeve upper housingremoved to show a dial for rotating an outer cannula;

FIG. 19 is a partial side cross-sectional view of the portion of thetissue cutting device of FIG. 18;

FIG. 20 is a side elevation view of an inner and outer cannula assemblyof the tissue cutting device of FIG. 1;

FIG. 21A is a tissue cutting system including a remote tissue collector,control console, foot pedal, and the tissue cutting device of FIG. 1;

FIG. 21B is an enlarged view of the remote tissue collector of FIG. 21A;

FIG. 22 is a block diagram of a control scheme for the tissue cuttingsystem of FIG. 22;

FIG. 23 is diagram of the tissue cutting device of FIG. 1 and the motorcontrol unit of FIG. 22;

FIG. 24 is a partial cross-sectional view of the tissue cutting deviceof FIG. 1 depicting motor shaft position sensors for controlling a stopposition of an inner cannula;

FIG. 25 is a partial cross-sectional view of the outer cannula and innercannula of the tissue cutting device of FIG. 1 with the inner cannula ina first position relative to the outer cannula;

FIG. 26 is a partial cross-sectional view of the outer cannula and innercannula of the tissue cutting device of FIG. 1 with the inner cannula ina second position relative to the outer cannula;

FIG. 27 is a partial cross-sectional view of the outer cannula and theinner cannula of the tissue cutting device of FIG. 1 with the innercannula in a third position relative to the outer cannula; and

FIG. 28 is a side elevational view of the irrigation sleeve of FIG. 1;

FIG. 29 is a partial close-up, longitudinal cross-sectional view of thedelivery sleeve, outer cannula and inner cannula of FIG. 1;

FIG. 30 is a transverse cross-sectional view taken along line 30-30 inFIG. 29;

FIG. 31 is a close-up, partial side elevational view of the deliverysleeve of FIG. 1 selectively disposed along the length of the outercannula of FIG. 1; and

FIG. 32 is a close-up, partial top plan view of the delivery sleeve ofFIG. 1 selectively disposed over a portion of the outer cannula openingof FIG. 1.

FIG. 33 is a partial perspective view of an alternative embodiment of adelivery sleeve mounted on a tissue cutting device.

FIG. 34 is an exemplary configuration of an end view of the deliverysleeve of FIG. 33.

FIG. 35 is a perspective view of a hub for supporting the deliverysleeve of FIG. 33.

FIG. 36 is a cross-sectional view of the hub of FIG. 35.

FIG. 37 is an end view of the hub of FIG. 35.

FIG. 38 is side elevational view of the hub of FIG. 35.

FIG. 39 is a partial perspective view of the delivery sleeve mounted ona tissue cutting device connected to a fluid supply.

FIG. 40 is an end view of the delivery sleeve of FIG. 39.

FIG. 41 is a perspective view of an alternative hub for supporting adelivery sleeve.

FIG. 42 is a cross-sectional view of the hub of FIG. 41.

FIG. 43 is an end view of the hub of FIG. 41.

FIG. 44 is side elevational view of the hub of FIG. 41.

DETAILED DESCRIPTION

Referring now to the discussion that follows and also to the drawings,illustrative approaches to the disclosed systems and methods are shownin detail. Although the drawings represent some possible approaches, thedrawings are not necessarily to scale and certain features may beexaggerated, removed, or partially sectioned to better illustrate andexplain the present disclosure. Further, the descriptions set forthherein are not intended to be exhaustive or otherwise limit or restrictthe claims to the precise forms and configurations shown in the drawingsand disclosed in the following detailed description.

Described herein are tissue cutting devices that are suited forneurosurgical applications such as the removal of spine and braintissue. The devices are configured with a delivery sleeve that isdisposed on an outer cannula and selectively positionable along thelength of the outer cannula. As a result, the tissue cutting devices cansimultaneously provide, without the need for removal of the tissuecutting device from the surgical site, delivery of fluids such asirrigants, hemostatic agents, and tissue sealants to a surgical site andother devices complementary to the tissue removal device and accretiveto the surgical procedure. They can also be used to selectively adjustthe area of the outer cannula aperture through which the aspiration isdelivered through to the tissue.

Referring to FIG. 1, a tissue cutting device 40 includes a handpiece 42and an outer cannula 44. In one exemplary embodiment, handpiece 42 isgenerally cylindrical in shape and is preferably sized and shaped to begrasped with a single hand. Handpiece 42 includes a lower housing 50which comprises a proximal section 46 and distal section 48. Lowerhousing 50 comprises a proximal-most housing portion 82 (FIGS. 2 and 3)that is connected to a motor housing 71, and a cam housing 69 that isconnected to motor housing 71. A front housing section 51 is connectedto cam housing 69. Upper housing 52 is also provided. A tissue collector58 may be operatively connected to upper housing 52 (as will beexplained in further detail below). A rotation dial 60 for rotating theouter cannula 44 with respect to handpiece 42 is also mounted to upperhousing 52.

As best seen in FIGS. 2, 3, and 20, outer cannula 44 includes an openproximal end 45, a closed distal end 47, and a distal opening 49proximate distal end 47. Tissue cutting device 40 further comprises aninner cannula 76 which is partially disposed in an outer cannula lumen110 (FIG. 8). Inner cannula 76 is configured to reciprocate within outercannula lumen 110 and to cut tissue samples entering outer cannula 44via outer cannula distal opening 49, as will be described in greaterdetail below. Inner cannula 76 reciprocates between a proximal position,which is depicted in FIG. 2 and a distal position which is depicted inFIG. 3. Inner cannula 76 includes an open proximal end 77 and an opendistal end 79. Distal end 79 is preferably configured to cut tissue, andin preferred embodiments is capable of cutting neurological systemtissues such as those from the brain or spine. In one exemplaryembodiment, inner cannula distal end 79 is beveled in a radially inwarddirection to create a sharp circular tip and facilitate tissue cutting.

Outer cannula 44 is not translatable, and its position with respect tohandpiece 42 along the direction of the longitudinal axis of handpiece42 remains fixed. Delivery sleeve 302 (FIG. 1) is selectively attachableto outer cannula 44 and allows fluids and devices to be providedproximate a surgical site. Delivery sleeve 302 has a proximal hub 306and a distal end 320. An outer cannula opening 322 is provided at theproximal end of delivery sleeve 302. Elongated channel section 304 isconnected to proximal hub 306 and projects distally away from it. Distalend 320 of delivery sleeve 302 is the distal end of the elongatedchannel section 304. In FIG. 1, delivery sleeve 302 is shown in aninstalled condition on outer cannula 44. In the depicted installedcondition, delivery sleeve 302 is selectively positionable along thelength of outer cannula 44.

In FIGS. 2-3, delivery sleeve 302 is not shown for ease of viewing.Motor 62 is disposed in proximal lower housing section 46 of handpiece42 and is operably connected to inner cannula 76 to drive thereciprocation of inner cannula 76 within outer cannula lumen 110. Motor62 may be a reciprocating or rotary motor. In addition, it may beelectric or hydraulic. However, in the embodiment of FIGS. 2 and 3,motor 62 is a rotary motor, the rotation of which causes inner cannula76 to reciprocate within outer cannula lumen 110.

Motor 62 is housed in motor housing 71, which defines a portion of lowerhousing proximal section 46. Motor 62 is connected to an inner cannuladrive assembly 63 which is used to convert the rotational motion ofmotor 62 into the translational motion of inner cannula 76. At itsproximal end, motor housing 71 is connected to proximal-most housingportion 82, which includes a power cable port 84 and a hose connector43, which in the exemplary embodiment of FIG. 3 is an eyelet. Hoseconnector 43 provides a means of securely retaining a vacuum system hoseto handpiece 42, thereby allowing vacuum to be supplied to tissuecollector 58.

Inner cannula driver assembly 63 (not separately shown in figures)comprises a cam 64, a cam follower 68, a cam transfer 72, and a cannulatransfer 74. Cam 64 is a generally cylindrical structure and is shown indetail in FIGS. 16A and 16B. A groove or channel 65 is defined in thesurface of cam 64. In one exemplary embodiment, groove 65 is continuousand circumscribes the perimeter of cam 64 but is not orientedperpendicularly to the longitudinal axis of cam 64, i.e., groove 65 isangled with respect to the cam axis. Opposing points on groove 65 suchas points 65 a and 65 b (FIGS. 2 and 3) define pairs of “apexes” thatare spaced apart along the longitudinal axis of the cam, i.e., thegroove extends along a portion of the length of the cam. Cam 64 alsoincludes a proximal opening 114 (FIG. 16 a) for receiving a motor shaftand a proximal recess 116 into which a shaft may be snugly received.Holes 118 and 120 are provided for mounting position indicators thatcooperate with a position sensor to determine the angular position ofcam 64, and correspondingly, the linear position of inner cannula 76within the outer cannula lumen 110, as discussed below.

Cam follower 68 is depicted in detail in FIG. 17B. Cam follower 68 is agenerally rectangular block shaped structure with a hollow interior inwhich cam 64 is partially disposed. Cam follower 68 also includes a hole70 in its upper face in which a ball bearing (not shown) is seated. Theball bearing rides in cam groove 65 and engages cam transfer 72. As aresult, when cam 64 rotates, cam follower 68 translates along the lengthof handpiece 42. Cam follower 68 also includes lateral slots 182 a and182 b that cooperatively engage corresponding members 178 a, 178 b fromcam transfer 72.

Cam follower 68 is disposed within a cam chamber 67 formed in camhousing 69. Cam 64 is partially disposed in cam chamber 67 and extendsproximally therefrom to engage motor 62. Cam housing 69 comprises partof distal portion 48 of handpiece 42. Cam 64 does not reciprocate withincam chamber 67 and instead merely rotates about its own longitudinalaxis. However, cam follower 68 reciprocates within cam chamber 67 alongthe direction of the length of handpiece 42. Cam follower 68 is open atits proximal end to receive cam 64. As shown in FIGS. 15 and 16A, cam 64may optionally include a threaded distal end 123 that projects through adistal opening 191 (FIG. 17 b) in cam follower 68 and which engages anut 190 (FIG. 15) to prevent reciprocation of cam 64 relative to camhousing 69. Proximal cam bearing 186 and distal cam bearing 188 (FIG.15) may also be provided to support cam 64 as it rotates within camhousing 69.

Cam transfer 72 extends from cam chamber 67 into a cam transfer chamber73 formed in upper housing 52. As best seen in FIG. 17 a, cam transfer72 comprises a proximal end 72 a that is attachable to cam follower 68and a distal end 72 b that is attachable to inner cannula 76 via cannulatransfer 74. Proximal end 72 a comprises a pair of spaced apart,downwardly extending members 178 a and 178 b, and distal end 72 bcomprises a pair of spaced apart upwardly extending members 180 a and180 b. Downwardly extending members 178 a and 178 b are spaced apart ina direction that is perpendicular to the length of cam 64 and handpiece42, while upwardly extending members 180 a and 180 b are spaced apart ina direction that is parallel to the length of cam 64 and handpiece 42.Cam follower slots 182 a and 182 b engage downwardly extending members178 a and 178 b of cam transfer 72. Downwardly extending members 178 aand 178 b of cam transfer 72 may be resilient and may have engagementportions 179 a and 179 b on their free ends (e.g., hooks or clips) forsecurely engaging the bottom and side surfaces of cam follower 68.

As best seen in FIG. 20, cannula transfer 74 comprises a sleeve disposedabout inner cannula 76. For ease of viewing, delivery sleeve 302 is notshown in FIG. 20. Cannula transfer 74 comprises a proximal end 128,middle section 127, and distal end 126. Upwardly extending members 180 aand 180 b of cam transfer 72 define fork-shaped structures that receiveand cradle middle section 127 of cannula transfer 74. Distal end 126 andproximal end 128 of cannula transfer 74 are disposed outwardly ofupwardly extending members 180 a and 180 b and are shaped to preventrelative translation between cam transfer 72 and cannula transfer 74. Inthe depicted embodiments, distal end 126 and proximal end 128 of cannulatransfer 74 are enlarged relative to middle section 127 to abut theupwardly extending, fork-shaped members 182 a and 182 b, therebypreventing relative translation between cam transfer 72 and cannulatransfer 74. As a result, when cam transfer 72 reciprocates along thelength of handpiece 42, cannula transfer 74 reciprocates as well.Because it is affixed to inner cannula 76, when cannula transfer 74reciprocates, it causes inner cannula 76 to reciprocate within outercannula 44.

In one exemplary arrangement, motor 62 is a brushed DC motor and may beoperably connected to cam 64 in a number of ways. In the embodiment ofFIGS. 2 and 3, motor 62 includes a distally extending shaft 66 thatextends into a proximal opening 114 and engages recess 116 (FIGS. 16Aand B) defined in cam 64. Shaft 66 may be connected to cam 64 via athreaded connection, adhesive, or other known connection means. In analternate implementation, depicted in FIG. 15, a separate cam coupler184 is provided. Cam coupler 184 is seated in proximal opening 114 andhas a width greater than the diameter of opening 114. Cam coupler 184 isalso connected to motor shaft 66 such that rotation of shaft 66 causescam coupler 184 to rotate, which in turn causes cam 64 to rotatetherewith. One revolution of motor shaft 66 causes cam 64 to rotate byone revolution, which in turn causes inner cannula 76 to reciprocate byone complete stroke, i.e., from the position of FIG. 2 to the positionof FIG. 3 and back to the position of FIG. 2.

Cam transfer 72 may be connected to cam follower 68 by mechanical means,adhesive means or other known connection means. In one exemplaryembodiment, downwardly extending members 178 a and 178 b mechanicallyclip onto and removably engage cam follower 68. In another embodiment,cam transfer 72 is adhesively affixed to cam follower 68. In yet anotherembodiment, both mechanical and adhesive connections are used. The ballbearing (not shown) disposed in cam follower hole 70 traverses camgroove 65 as cam 64 rotates, causing cam follower 68 to reciprocate fromthe proximal position of FIG. 2 to the distal position of FIG. 3. As aresult, cam transfer 72, cannula transfer 74 and inner cannula 76translate between their respective proximal positions of FIG. 2 andtheir respective distal positions of FIG. 3 when motor 62 and cam 64rotate.

Motor 62 is preferably selected to have a rotational speed that allowsinner cannula 76 to reciprocate from the position of FIG. 2 to theposition of FIG. 3 and back to the position of FIG. 2 at a rate of atleast about 1,000 reciprocations/minute. Reciprocation rates of at leastabout 1,200 reciprocations/minute are more preferred, and reciprocationrates of at least about 1,500 reciprocations/minute are even morepreferred. Reciprocation rates of less than about 2,500reciprocations/minute are preferred. Reciprocation rates of less thanabout 2,000 are more preferred, and reciprocation rates of less thanabout 1,800 reciprocations/minute are even more preferred. As best seenin FIG. 14, the rates of reciprocation of device 40 allow tissue to besevered into “snippets” 112 which are relatively smaller than “slug”tissue samples obtained by many prior devices. As the reciprocationcontinues, a continuum of severed tissue snippets 112 is obtained.

As mentioned previously, outer cannula 44 includes an opening 49 forreceiving tissue into outer cannula lumen 110. As best seen in FIGS.8-12, opening 49 is preferably defined by a cutting edge 51 that isconfigured to sever tissue and a non-cutting edge 53 that is notconfigured to sever tissue. In certain exemplary implementations,cutting edge 53 has a radial depth “d” that is no greater than about 50%of the outer diameter of outer cannula 44. In one exemplaryimplementation, cutting edge 51 is beveled in a radially inwarddirection, non-cutting edge 53 is not beveled, and cutting edge 51 islocated immediately distally of non-cutting edge 53. Inner cannuladistal end 79 is preferably configured to cut tissue. In one exemplaryembodiment, distal end 79 is beveled in a radially inward directionaround the circumference of inner cannula 76 to provide a sharp edge. Astissue is received in outer cannula opening 49, it is compressed betweeninner cannula distal end 79 and outer cannula cutting edge 51, causingthe received tissue to be severed from the surrounding tissue.

Tissue cutting device 40 is particularly well suited for use in cuttingtough tissues such as spinal and brain tissues. Outer cannula 44 andinner cannula 76 comprise materials that are generally rigid, such asrigid plastics or metal. In one preferred implementation, both cannulasare constructed of stainless steel, and more preferably, 304SS typicallyused in medical grade instruments.

As best seen in FIGS. 9-14, to facilitate the cutting of tough tissues,inner cannula 76 includes a hinge 80. For ease of viewing, deliverysleeve 302 is not shown in FIGS. 9-14. Hinge 80 is located between innercannula body section 81 which is located on the proximal side of hinge80 and inner cannula cutting section 83 which is located on the distalside of hinge 80. In one exemplary arrangement, hinge 80 is a livinghinge. As used herein, the term “living hinge” refers to a thin,flexible hinge that joins two relatively more rigid parts together. Inone example, hinge 80 is a living hinge that is integrally formed withinner cannula body section 81 and inner cannula cutting section 83 byremoving a portion of the circumference of the inner cannula 76 along alength L (FIG. 11). Hinge 80 allows cutting section 83 to pivot abouthinge 80 as inner cannula 76 reciprocates within outer cannula 44. Asinner cannula 76 translates in the distal direction, it contacts tissuereceived in outer cannula opening 49 and encounters progressivelyincreasing resistance from the tissue as the tissue is urged in thedistal direction. As the resisting force of the tissue increases,cutting section 83 pivots progressively more until a zero annularclearance is obtained between inner cannula distal end 79 and outercannula opening 49. The received tissue is severed and aspirated in theproximal direction along inner cannula lumen 78 and received in tissuecollector 58. Thus, inner cannula lumen 78 provides an aspiration pathfrom the inner cannula distal end 79 to the inner cannula proximal end77. Hinge 80 allows a generally zero annular clearance to be obtainedbetween inner cannula distal end 79 and outer cannula opening 49 atcutting section 83 while not affecting the annular clearance betweeninner cannula body section 81 and outer cannula 44. This configurationmaximizes tissue cutting while minimizing frictional losses that wouldotherwise occur due to the frictional engagement of the outer surface ofinner cannula body section 81 and the inner surface of outer cannula 44if a very small annular clearance between the outer cannula 44 and innercannula 76 were present.

Outer cannula opening 49 may have a number of shapes. In certainexamples, when outer cannula opening 49 is viewed in plan, it has ashape that is generally square, rectangular, trapezoidal, ovular, or inthe shape of the letter “D.” In certain other exemplary implementations,outer cannula opening 49 is configured to direct tissue so that it maybe compressed as inner cannula 76 translates in the distal direction. Inone exemplary embodiment, depicted in FIGS. 10 and 12, outer cannulaopening 49 has a generally triangular shape when outer cannula opening49 is viewed in plan. As FIGS. 10 and 12 indicate, when viewed in plan,the width of opening 49 in a direction transverse to the outer cannulalongitudinal axis varies longitudinally along the length of outercannula 44, and preferably narrows from the proximal to distal portionsof opening 49. When viewed in side elevation, cutting edge 51 slopes ina radially outward direction moving distally along edge 51. As a result,as a tissue sample is distally urged within outer cannula opening 49 bythe action of inner cannula 76, the tissue is increasingly compressed inthe direction of the circumference of inner cannula 76 (or in thedirection of the “width” of opening 49 when viewed in plan). To ensurecomplete cutting, inner cannula distal end 79 preferably travels to aposition that is distal of outer cannula opening 49 during a tissuecutting operation, i.e., there is an inner cannula overstroke.

As mentioned above, tissue cutting device 40 aspirates tissue samplesreceived in inner cannula lumen 78 to cause the tissue samples to movein the proximal direction along the length of the inner cannula 76. Incertain methods of use, device 40 is used to resect tissue withoutcollecting tissue samples for further analysis. In such embodiments, atissue collector need not be provided. In other embodiments whereintissue collection is desired, device 40 preferably includes a tissuecollector 58 into which aspirated tissue samples are deposited during atissue cutting procedure. Tissue collector 58 may be located remotelyfrom handpiece 42 and outside the sterile field during a tissue cuttingoperation as shown in FIG. 21A. However, in an alternative embodiment,as best seen in the examples of FIGS. 1-7, tissue collector 58 isremovably connected to handpiece 42. In either embodiment, a fluidcollection canister 192 is preferably located between tissue collector58 and a source of vacuum (such as vacuum generator 153 in FIG. 21A) toprotect the vacuum generating apparatus from becoming contaminated ordamaged by aspirated fluids. In those embodiments that lack a tissuecollector, fluid collection canister 192 may be provided to collect bothaspirated fluid and tissue.

Referring to FIGS. 4-7, tissue collector 58 is connected to upperhousing 52 proximally of the inner cannula 76 to receive the aspiratedtissue samples. Tissue collector 58 is a generally cylindrical, hollowbody with an interior volume that is in fluid communication with theinner cannula lumen 78 and a source of vacuum (not shown in FIGS. 4-7).Tissue collector 58 is removably secured to housing connector 96 toallow for the periodic removal of collected tissue samples. Tissuecollector 58 is preferably secured to upper housing 52 in a manner thatprovides a substantially leak-proof vacuum seal to maintain consistentaspiration of severed tissue samples. A vacuum hose fitting 59 is formedon the proximal end of tissue collector 58 and is in fluid communicationwith the interior of tissue collector 58 and with a vacuum generator, aswill be discussed below.

In the embodiment of FIGS. 4-5, housing connector 96 is a generallycylindrical, flange extending proximally from upper housing 52. Uppershell 54 and lower shell 56 of upper housing 52 cooperatively define acavity into which a seal holder 94 is partially disposed. Seal holder 94includes a distal annular recess in which a seal 92, such as an o-ring,is disposed. Seal holder 94 also includes a central lumen through whichinner cannula 76 is slidably disposed. A proximally projecting portion95 of seal holder 94 projects away from upper housing 52 in the proximaldirection and is received within housing connector 96. As best seen inFIGS. 2 and 3, inner cannula proximal end 77 preferably remains withinseal holder 94 as inner cannula 76 reciprocates during operation oftissue cutting device 40. However, proximal end 77 moves within sealholder 94 as inner cannula 76 reciprocates. Seal 92 preferably comprisesa resilient material such as an elastomeric material. The sealingengagement of seal 92 and inner cannula 76 prevents air or fluids fromleaking between inner cannula 76 and upper housing 52 and aids inmaintaining consistent aspiration of samples through the inner cannulalumen 78.

Housing connector 96 includes connecting features 98 and 100 which areconfigured to engage with corresponding connecting features 102 and 104on tissue collector 58. In the embodiment of FIGS. 4 and 5, connectingfeatures 98 and 100 are “J” shaped slots formed in housing connector 96,and connecting features 102 and 104 are complementary protrusions formedon tissue collector 58 which engage connecting features 98 and 100,respectively. To connect tissue collector 58 to housing connector 96,protrusions 102 and 104 are aligned with slots 98 and 100, and tissuecollector 58 is then inserted into housing connector 96 in the distaldirection. Tissue collector 58 is then rotated to fully engageprotrusions 102 and 104 with slots 98 and 100. A seal 103 is providedaround the circumference of tissue collector 58 to sealingly engage theinner surface of housing connector 96.

An alternate embodiment of tissue collector 58 is depicted in FIGS. 6and 7. In the embodiment of FIGS. 6 and 7, tissue collector 58 issemi-elliptical in cross-section and includes a hollow interior forreceiving samples, as in the embodiment of FIGS. 4 and 5. In theembodiment of FIGS. 6 and 7, a cylindrical flange housing connector 96is not provided. Instead, upper housing 52 is formed with an engagementrecess 108 that engages a complementary clip 106 formed on tissuecollector 58. In each of the foregoing embodiments, tissue collector 58may be provided with a filter (not shown) in its interior for collectingsolid tissue samples while allowing liquids and gases (e.g., air) topass through. Exemplary filters include medical grade mesh filters witha mesh size smaller than that of tissue snippets 112.

In the embodiments of FIGS. 4-7, tissue collector 58 preferably has alongitudinal axis that is not collinear with the longitudinal axes ofhandpiece 42, motor 62, or cam 64. The longitudinal axis of tissuecollector 58 is preferably substantially coaxial with the longitudinalaxis of inner cannula 76 to yield an “in-line” filter configuration.Tissue collector 58 and inner cannula 76 are both spaced apart from andsubstantially parallel to the longitudinal axes of handpiece 42, motor62, and cam 64. Thus, the cutting axis (i.e., the outer cannulalongitudinal axis) and sample aspiration path axis are not coaxial withthe longitudinal axis of the handpiece 42. As a result, when device 40is used to cut tissue, the surgeon's view of the cutting axis is notobstructed by his or her hand. In addition, the surgeon can treat theproximal end of the filter as a “gun sight” and align it with a tissuesample to be cut to thereby align the outer cannula 44 with the tissuesample, providing enhanced ergonomic benefits over previous devices, inparticular, previous neurosurgical devices. In the case of a device witha remote tissue collector 58 such as the one depicted in FIGS. 21A and21B, the user can treat the proximal end of upper housing 52 as a gunsight and align it with a target tissue.

When device 40 is used to cut tissue, outer cannula opening 49 must bealigned with the target tissue of interest to receive it for cutting.The entire device 40 can be rotated about the longitudinal axis ofhandpiece 42 to place outer cannula opening 49 at the desired location.However, this technique can be awkward and may reduce the surgeon'sdexterity. Thus, in an exemplary embodiment, device 40 includes aselectively rotatable outer cannula 44. As best seen in FIGS. 18-20, arotation dial 60 is provided and is rotatably seated in a cavity definedby upper shell 54 and lower shell 56 of upper housing 52. Rotation dial60 is configured such that when it is rotated, it causes outer cannula44 to rotate about its longitudinal axis with respect to handpiece 42.Rotation dial 60 is preferably connected to an outer cannula connectorportion 88. In the embodiment of FIGS. 18-20, outer cannula connectorportion 88 is a sleeve that is integrally formed with rotation dial 60and which is fixedly secured to outer cannula 44 such as by an adhesiveor other known connection means. In the exemplary embodiment of FIG. 20rotation dial 60 has an outer diameter that is greater than that ofsleeve 88. For ease of viewing, fluid supply sleeve 302 is not shown inFIG. 20.

As mentioned previously, inner cannula 76 includes a hinge 80 to allowinner cannula cutting section 83 to pivot toward outer cannula opening49 when device 40 is in operation. In order to ensure the correctoperation of hinge 80, the circumferential alignment of hinge 80 andouter cannula opening 49 should be maintained. Thus, rotation dial 60 ispreferably connected to inner cannula 76 such that when rotation dial 60is rotated, both outer cannula 44 and inner cannula 76 rotate in a fixedangular orientation with respect to one another by an amount thatdirectly corresponds to the amount by which rotation dial 60 is rotated.Rotation dial 60 may be directly connected to inner cannula 76 or mayuse an intervening connecting device. However, rotation dial 60 shouldbe configured to allow inner cannula 76 to reciprocate with respect torotation dial 60. As best seen in FIG. 20, rotation dial inner cannulaconnector 86 may be provided to connect rotation dial 60 to innercannula 76. Rotation dial inner cannula connector 86 comprises aproximal sleeve 87 disposed about inner cannula 76 and a distal,radially extending annular flange 90 with an outer diameter greater thanthat of the sleeve 87. Sleeve 87 and flange 90 may be in the shape ofcircular cylinders. Alternatively, and as shown in FIGS. 18-19, sleeve87 and flange 90 may be in the shape of polygonal cylinders. Sleeve 87is slidably received within the annular cavity 130 at the distal end 126of the cannula transfer 74 and keyed to the inner surface of cannulatransfer 74 at annular cavity 130 such that sleeve 87 can reciprocatewith respect to cannula transfer 74 while causing cannula transfer 74 torotate with sleeve 87 when rotation dial 60 is rotated. When innercannula 76 is reciprocated, cannula transfer distal end 126 reciprocateswith respect to sleeve 87, thereby variably adjusting gap “G” definedwithin annular cavity 130 (FIG. 20). Alternatively, cannula transferdistal end 126 may be slidably received in an annular cavity formed insleeve 87 and may be keyed to the inner surface of the annular cavity sothat cannula transfer may reciprocate with respect to sleeve 87 whilestill rotating with sleeve 87 when dial 60 is rotates.

As best seen in FIG. 20, rotation dial 60 includes a first annularcavity 61 that is sized to receive and engage flange 90 in a closefitting relationship. Rotation dial 60 may be press fit to flange 90. Inaddition, adhesive connections or mechanical connections may be used.Because rotation dial 60 is directly or indirectly connected to bothouter cannula 44 and inner cannula 76, both cannulas rotate in directcorrespondence to the rotation of rotation dial 60, thereby allowing theuser to adjust the orientation of outer cannula opening 49 and innercannula hinge 80 in a circumferential direction with respect tohandpiece 42. As a result, surgeons need not rotate the entire tissuecutting device 40 to obtain the desired angular orientation.

Rotation dial 60, outer cannula 44, and inner cannula 76 are preferablyconfigured for 360° rotation. In addition, tactile indicators arepreferably provided on rotation dial 60 to allow a user to reliablydetermine the extent to which dial 60 has been rotated from a givenstarting point. The tactile indication may comprise surface featuresdefined on or in the exterior surface of rotation dial 60. In oneexemplary embodiment, depicted in FIGS. 18-20, a plurality of ridges 122is provided around the circumference of rotation dial 60 to providetactile indication. The ridges also act as grips and facilitate thesurgeon's ability to rotate the dial 60 without transferring unwantedmotion to the surgical site.

As mentioned previously, vacuum (sub-atmospheric pressure) is applied totissue collector 58 to aspirate severed tissue samples through innercannula 76 in the proximal direction. The application of vacuum to innercannula 76 via tissue collector vacuum hose fitting 59 will have apropensity to produce a vacuum at proximal end 45 of outer cannula 44 ifleakage occurs between inner cannula 76 and the components of upperhousing 52. The generation of a vacuum at outer cannula proximal end 45will in turn cause fluids and/or tissue samples at the distal end ofouter cannula 44 to flow into the annular clearance between innercannula 76 and outer cannula 44 that extends from its proximal end atouter cannula proximal end 45 to its distal end at inner cannula distalend 79. This fluid and/or tissue can result in blockage of the annularclearance and increased friction between the inner cannula 76 and outercannula 44, resulting in degraded performance. Accordingly, a seal 129is preferably provided to prevent air artifacts, fluid (water, saline,blood, etc.) flow, and tissue sample flow in the annular clearancebetween inner cannula 76 and outer cannula 44. The seal 129 ispreferably disposed adjacent the proximal end of the annular clearancebetween inner cannula 76 and outer cannula 44, i.e., proximally adjacentto outer cannula proximal end 45. As shown in FIG. 20, seal 129 ispreferably annular and circumscribes inner cannula 76, extending fromthe outer surface of inner cannula 76 in a radially outward direction aswell as longitudinally along a portion of the length of inner cannula76.

In the embodiment of FIG. 20, rotation dial 60 and sleeve 87 act as aseal housing and include a seal cavity 131 which is an annular cavitydisposed immediately adjacent to and distal of first annular cavity 61.Seal cavity 131 is sized to accept seal 129 therein. The seal 129 may bea conventional seal such as a solid, flexible and/or elastomeric o-ring.However, seal 129 is preferably amorphous and comprises a thixotropicmaterial that is a semi-solid. It is further preferred that seal 129fill the entirety of seal cavity 131 to ensure that cavity 131 issubstantially leak free. In the exemplary embodiment of FIG. 20, sealcavity 131 has an outer diameter that is greater than the outer diameterof outer cannula 44. Moreover, the annular thickness of seal cavity 131is preferably greater than the annular clearance between outer cannula44 and inner cannula 76 to better ensure complete sealing of the annularclearance.

In one exemplary embodiment, seal 129 is a grease—such as the so-called“high vacuum greases”—that is formulated to withstand vacuum conditions.Suitable high vacuum greases include halogenated polymers. Thehalogenated polymers are preferably based on cyclic ether or unsaturatedhydrocarbon polymeric precursors. In one exemplary embodiment, aperfluroropolyether (PFPE) grease is used. Examples of such greasesinclude the FOMBLIN® family of greases supplied by Solvay Solexis, Inc.Other examples of such greases include polytetrafluroroethylene greases(“PTFE”) such as TEFLON® greases supplied by DuPont. One suitable highvacuum grease is FOMBLIN® Y VAC3 grease, which is a PFPE grease with aPTFE thickener. The semi-solid seal 129 preferably has a kinematicviscosity at 20° C. of at least about 500 cSt, more preferably at leastabout 800 cSt, and even more preferably at least about 1200 cSt.Semi-solid seal 129 preferably has a kinematic viscosity at 20° C. of nogreater than about 2500 cSt, more preferably no greater than about 2000cSt, and even more preferably no greater than about 1700 cSt.

The use of a semi-solid seal 129 has several advantages. Because theseal is semi-solid, it will tend to absorb and dampen vibrationstransmitted from the reciprocation of the inner cannula, therebyreducing overall vibration of device 40, and in particular, thevibration transmitted to outer cannula 44. The dampening of suchvibrations is particularly beneficial because it reduces thetransmission of unwanted vibrations to outer cannula 44 which candisturb delicate neurosurgical procedures. Moreover, because it is not asolid seal, seal 129 will experience less heating and wear as it isfrictionally engaged by the reciprocating inner cannula 76. In certainembodiments, a portion of seal 129 will adhere to the outer surface ofinner cannula 76 as it reciprocates producing a zero slip velocitycondition at the inner cannula 76 outer surface which may further reducefrictional heating and degradation of seal 129. Because semi-solid seal129 produces less frictional resistance to the reciprocation of innercannula 76 as compared to conventional solid seals such as o-rings, italso decreases the required motor power consumption and can facilitatethe use of lower torque and lower cost motors, which in turn facilitatesmaking device 40 disposable.

In one configuration, device 40 is connected to a vacuum source andconfigured for variable aspiration, i.e., configured to supply variablelevels of vacuum to inner cannula lumen 78. As depicted in FIG. 21A, inone exemplary implementation, a tissue cutting system is provided whichcomprises tissue cutting device 40, a tissue collector 58, a controller132, a vacuum generator 153, a vacuum actuator 144, a controllable valve146, a vacuum line 151, and a fluid collection canister 192. Asmentioned previously, in FIG. 21A tissue collector 58 is locatedremotely from handpiece 42 and may be placed far enough from thehandpiece 42 to either be within the sterile field or be positionedoutside of the sterile field during a tissue cutting operation. As bestseen in FIG. 21B, tissue collector 58 is generally the same as thetissue collector 58 depicted in FIGS. 4-5. Vacuum line 151 a connectsthe distal end of tissue collector 58 to proximally projecting portion95 of seal holder 94 on the proximal end of tissue cutting device upperhousing 52. In one arrangement, the proximal end of vacuum line 151 aincludes a hose fitting 59 b that is integrally formed with a tissuecollector coupler 296. Coupler 296 is similar in structure to tissuecollector connector 96 (FIGS. 4-5) and is a cylindrical structure with ahollow interior for receiving a portion of tissue collector 58. As bestseen in FIG. 21B, tissue collector 58 includes projections 202 and 204which engage complementary slots 298 and 200 in coupler 296 in the samemanner that projections 102 and 104 engage slots 98 and 100 in FIGS.4-5. At the proximal end of tissue collector 58, hose fitting 59 aengages vacuum line 151 b which in turn is connected to fluid collectioncanister 192. Fluid collection canister 192 is connected to vacuumgenerator 153 via vacuum line 151 c. Vacuum generator 153 is connectedto controllable valve 146 by way of pressure line 147.

The outlet of fluid collection canister 192 is preferably substantiallyliquid free and is connected to vacuum generator 153 via vacuum line 151c. Thus, vacuum generator 153 is in fluid communication with tissuecollector 58 and inner cannula lumen 78, thereby generating a vacuum atthe proximal end 77 of inner cannula 76 to aspirate severed tissuesamples from inner cannula distal end 79 to tissue collector 58. Thelevel of vacuum generated by vacuum generator is preferably variable andselectively controllable by a user. Maximum vacuum levels of at leastabout 0 in Hg. are preferred, and maximum vacuum levels of at leastabout 1 in Hg. are more preferred. Maximum vacuum levels of at leastabout 5 in Hg. are even more preferred, and maximum vacuum levels of atleast about 10 in Hg. are still more preferred. Maximum vacuum levels ofat least about 20 in. Hg. are yet more preferred, and vacuum levels ofat least about 29 in. Hg. are most preferred.

The controllable valve 146 and the vacuum generator 153 provide a meansfor continuously adjusting and controlling the level of vacuum appliedto tissue collector 58 and the proximal end of inner cannula lumen 78.Controllable valve 146 is supplied with a pressurized gas, preferablyair, or an inert gas such as nitrogen. In one exemplary embodiment, thepressure applied to controllable valve 146 is about 70 psi.

The system further includes an electrical controller 132 which receivesand provides signals to the various components to control or monitortheir operations. Controller 132 provides control signals to device 40via motor drive control line 142 to activate or deactivate motor 62. Anaspiration valve control line 150 extends from the controller 132 to thecontrollable valve 146 which provides pressure to the vacuum generator153. Signals to the controllable valve 146 through line 150 are used tocontrol the amount of vacuum applied to tissue collector 58.

In one exemplary configuration, controller 132 may receive electricalsignals from the various components of the system. For instance if anclosed loop circuit is employed, a pressure transducer 148 associatedwith the aspiration controllable valve 146, may be configured to send asignal along line 152 to the controller 132. The signal isrepresentative of the pressure supplied through controllable valve 146to vacuum generator 153. Thus, the transducer 148 may be configured toprovide immediate feedback to the controller, which can in turn providesignals to aspiration controllable valve 146. However, it is understoodthat an open loop circuit may also be employed.

The user can adjust the system operating parameters by using panelcontrols such as a console knob 138 and/or one or more depressiblecontrollers, such as a foot pedal 144. In one embodiment, foot pedal 144can be used to activate the motor 62 in device 40, causing the innercannula 76 to reciprocate within the outer cannula 44. In anotherembodiment, foot pedal 144 can be used to control the vacuum levelsupplied from vacuum generator 153 to tissue collector 58 and innercannula lumen 78. In yet another embodiment, foot pedal 144 can be usedboth to activate motor 62 and to control the vacuum level supplied fromvacuum generator 153 to tissue collector 58. In one arrangement, footpedal 144 is configured to variably increase the level of vacuum appliedto tissue collector 58 from a minimum level to a maximum level as footpedal 144 is depressed from a first position to a second position. Insuch an arrangement, the first position is one in which foot pedal 144is not depressed all or is only slightly depressed, and the secondposition is one in which foot pedal 144 is fully depressed. In anotherembodiment, knob 138 is used to set a preselected maximum vacuum levelapplied by vacuum generator 153. Thus, by depressing foot pedal 144 froma first fully open position to a second fully closed position, aplurality (preferably a continuum) of vacuum levels can be supplied totissue collector 58 with the maximum vacuum level being user adjustablevia knob 138.

In one exemplary embodiment, foot pedal 144 includes two switches (notshown) for providing variable vacuum and activating motor 62. In anotherexemplary embodiment, once foot pedal 144 is partially depressed from anopen or undepressed position, motor 62 is activated. In accordance withthe embodiment, continued depression of foot pedal 144 activates vacuumgenerator 153. Foot pedal 144 preferably provides continuous movementbetween a fully open and a fully depressed position which in turncorresponds to a plurality, and preferably a continuum, of vacuum levelsthat are supplied to inner cannula lumen 78. Once foot pedal 144 isfully depressed, the vacuum level supplied to inner cannula lumen 78corresponds to a previously selected maximum vacuum level.

In certain illustrative examples, the user will adjust the level ofvacuum to achieve a desired level of “traction” in the tissuesurrounding the tissue to be severed. As used herein, the term“traction” refers to the exertion of a pulling force on tissuesurrounding the target tissue to be severed. In some instances, tractionmay be visualizable by the surgeon with the use of a magnificationinstrument, such as a microscope or an endoscope. The level of vacuumwill also determine the amount of unsevered tissue that is drawn intoouter cannula opening 49, and therefore, the size of the severed tissuesnippets 112 (FIG. 14). Therefore, when fine shaving operations aredesired, the vacuum level will be a relatively lower level than ifdebulking (large scale tissue removal) is performed. Of course, thepre-selected maximum vacuum level will also affect the maximum size oftissue that is drawn into outer cannula opening 49, and therefore, willaffect the maximum size of severed tissue samples during any oneoperation. Also, the vacuum level may be adjusted based on theelasticity, fibrotic content, and hardness/softness of the tissue.

Console 134 may also include indicator lights 136, one of whichindicates the activation of cutting and one of which indicates theactivation of aspiration. Console 134 may further include an analogdisplay 140 with readouts for “aspiration” and “cutter.” The“aspiration” read out indicates the vacuum level supplied to tissuecollector 58 from vacuum generator 153. The “cutter” read out indicatesthe speed of reciprocation of inner cannula 76. In one embodiment, aspeed sensor is mounted in device 40 to determine the speed ofreciprocation of inner cannula 76 and the sensor is input to controller132.

As mentioned previously, when device 40 is used to perform a cuttingoperation, inner cannula 76 reciprocates within outer cannula opening 49to sever tissue received within outer cannula opening 49. When a cuttingoperation is complete, it may be preferred to have inner cannula 76 cometo rest at a position that is proximal of the proximal edge 53 of outercannula opening 49 to ensure that tissue is not trapped between innercannula distal end 79 and outer cannula cutting edge 51. However, incertain methods of use, tissue cutting device 40 may be used as anaspiration wand without cutting any tissue. In these embodiments, thestop position of the inner cannula distal end 79 within outer cannulaopening 49 determines the open area of the outer cannula 44, andtherefore, the aspiration levels that can be applied immediatelyadjacent outer cannula opening 49. Thus, in some preferred embodiments,the inner cannula stop position is user adjustable. Tissue cuttingdevice 40 may be used to aspirate a variety of fluids associated with aneurosurgical procedure, including without limitation blood, saline,cerebrospinal fluid, and lactated ringer's solution. In certainexamples, the inner cannula stop position is adjusted to provide adesired degree of aspiration, outer cannula 44 is positioned proximate atarget tissue, and vacuum is applied to manipulate the target tissue anddraw it into outer cannula opening 49. Outer cannula 44 is then moved toa desired location or orientation, thereby moving the target tissue tothe desired location or orientation. Once the target tissue has beensatisfactorily manipulated, a cutting operation is initiated. By usingdevice 40 in this manner, target tissues can be drawn away from areaswhere tissue cutting operations are undesirable, and the cutting can beperformed remotely from those areas.

In one exemplary system, an inner cannula position control is providedwhich controls the rest position of inner cannula 76 when motor 62 isdeactivated. Referring to FIG. 24, cam rotational position indicators176 a and 176 b are mounted on the proximal end of cam 64. In anexemplary embodiment, cam rotational position indicators 176 a and 176 bare magnets having opposite poles. A position sensor 174 is mounted onthe inner surface of cam housing 69 and generates a signal indicative ofthe rotational position of indicators 176 a and 176 b relative toposition sensor 174. As mentioned previously, the rotation of cam 64correlates directly to the position of inner cannula 76 within outercannula 44. Thus, the rotation of cam 64 can be sensed to indirectlydetermine the position of inner cannula 76. Accordingly, indicators 176a/176 b and sensor 174 can be used to determine the position of innercannula 76 with respect to proximal edge 53 of outer cannula opening 49(FIGS. 10-12).

Referring to FIG. 22, an embodiment of a system for controlling theoperation of tissue cutting device 40 is provided. The system includes amain control unit 158 (“MCU”), which (in the embodiment shown) isconfigured as a microprocessor-based system. In one implementation, MCU158 is incorporated in controller 132 (FIG. 21A) and is operable tocontrol the various operations of the tissue cutting device 40. Footswitch 144 is electrically connected to a number of inputs of MCU 158via an equal number, K, of signal paths 156, wherein K may be anyinteger. Panel controls, such as knob 138, are electrically connected toa number of inputs of MCU 158 via an equal number, J, of signal paths145, wherein J may be any integer.

Display unit 140 is electrically connected to a number of outputs of MCU158 via an equal number, Q, of signal paths 141, wherein Q may be anyinteger. In one exemplary implementation, depicted in FIG. 21A, displayunit 140 is provided on console 134.

As mentioned previously, tissue cutting device 40 includes motor 62coupled to the inner cannula 76 by an inner cannula drive assembly 63.The motor 62 is electrically connected to motor control unit 160 via anumber, M, of signal paths 161 wherein M may be any integer. The motorcontrol unit 160 is, in turn, connected to a number of outputs of MCU158 via an equal number, N, of signal paths 161. Cam rotational positionsensor 174 is electrically connected to a motor shaft position feedbackinput (SPF) of MCU 158 via signal path 162, and provides a motor stopidentification signal thereon as will be more fully describedhereinafter. The motor shaft stop identification signal provided bysensor 174 on signal path 162 preferably provides MCU 158 with a motorstop identification signal and may optionally provide a cutter speedsignal that is proportional to the motor speed for a geared system oridentical to the motor speed for a direct drive system.

Tissue cutting device 40 is further mechanically connected to a vacuumunit 168 (e.g., a combination of controllable valve 146 and vacuumgenerator 153 in FIG. 21A) via conduit 163 (not shown in FIG. 22),whereby the vacuum unit 168 provides a controllable vacuum level todevice 40 for aspirating tissue received in inner cannula lumen 78.Vacuum unit 168 is electrically connected to a vacuum control unit 166via a number, P, of signal paths 169 wherein P may be any integer. Thevacuum control unit 166 is, in turn, connected to a number of outputs ofMCU 158 via an equal number, L, of signal paths 167, wherein L may beany integer. A vacuum sensor 164, which may be a temperature compensatedsolid-state pressure sensor, may be positioned within the conduit 151and electrically connected to a vacuum feedback (VF) input of MCU 158via signal path 165. Alternatively, the vacuum sensor 164 may bedisposed within hand piece 42 or within the vacuum unit 168 itself.

In operation, the MCU 158 is responsive to a vacuum command signal,preferably provided by a corresponding control mechanism associated withcontrol panel 138, foot pedal 144, or an equivalent control mechanism,to provide one or more corresponding vacuum control signals to vacuumcontrol unit 166 along signal paths 167. The vacuum control unit 166, inturn, is responsive to the one or more vacuum control signals toactivate the vacuum unit 168 to thereby provide tissue cutting device 40with a desired level of vacuum. The actual vacuum level provided totissue cutting device 40 is sensed by vacuum sensor 164, which providesa corresponding vacuum feedback signal to the vacuum feedback input VFof MCU 158. The MCU 158 is then operable to compare the vacuum feedbacksignal with the vacuum command signal and correspondingly adjust the oneor more vacuum control signals to achieve the desired vacuum levelwithin tissue cutting device 40. Such closed-loop feedback techniquesare well known in the control systems art.

In one alternative embodiment, the MCU 158 can be replaced by individualmicroprocessors controlling the input and output for controlling theoperation of the motor 62 and the vacuum unit 168. In this alternativeembodiment, the motor control and vacuum control microprocessors can bePIC16CXX Series microcontrollers provided by Microchip, Inc. of ChandlerAriz. The motor control microcontrollers can receive input signals fromthe motor driver 172 (FIG. 23) and position sensor 174, as well as thefoot switch 144 and panel controls 138. Likewise, the vacuummicrocontroller can receive input signals from the vacuum sensor 164,the foot switch 144 and panel controls 138. Each microcontroller canprovide its own output to its driven component and have its own display,such as an LED display, indicative of its operational status. Moreover,the two units can communicate with each other to ensure clean cutting byproper timing of the cutting and aspiration functions.

Referring now to FIG. 23, one exemplary embodiment of the motor controlunit 160 is shown in greater detail. The motor control unit 160 in oneembodiment includes a pulse width modulation (PWM) generator circuit 170having a motor speed input connected to one of the MCU outputs 161 ₁. Ifmotor speed control is provided, the output 161 ₁ can provide a variablevoltage signal indicative of a desired motor speed and based upon theposition of a throttle, foot pedal, or other actuator. In certainembodiments, an additional input is connected to another one of the MCUoutputs 161 ₂. The signal at this output 161 ₂ can be a motor slowdownsignal as described below. Alternatively, the output 161 ₂ canconstitute a braking signal used in connection with a current feedbackmotor controller. As a further alternative, the slowdown command may becommunicated via the motor speed command itself, rather than through aseparate signal 161 ₂. In this instance, the output 161 ₂ may not berequired.

In the illustrated embodiment, the PWM is disposed within the motorcontrol unit 160. Alternatively, the PWM can be integrated into the MCU158, or into the separate motor control microprocessor discussed above.In embodiments that include motor speed control, the motor speed inputreceives a motor speed signal from MCU 158 indicative of desiredoperational speed of the motor 62. The slowdown input can receive aspeed adjustment signal from the MCU 158 based on an actual motor speedsignal provided by a motor sensor associated with the motor 62.

A motor driver circuit 172 is electrically connected to PWM generatorcircuit 170 via signal path 173 and receives a PWM drive signaltherefrom, which is a pulse width modulated signal indicative of desiredmotor speed. The motor driver circuit 172 provides a motor drive signal(MD) to motor 62 via signal path 175. While the disclosed embodimentcontemplates digital control of the motor using the PWM generatorcircuit 170, alternative embodiments can utilize closed loop feedbackanalog circuits, particularly where slower cutting speeds arecontemplated.

The motor drive signal includes a motor stop input that is connected toanother one of the MCU outputs 161 ₁. In accordance with an aspect ofthe present disclosure, MCU 158 provides a motor stop signal on signalpath 161 ₃, based on a motor deactivation command provided by footswitch 144 or panel control 138 and also based on a motor stopidentification signal provided by sensor 174, to stop the inner cannula76 in a desired position, as will be more fully described hereinafter.In certain embodiments, only the motor stop signal is utilized tocommand the motor to stop at the predetermined position. In thesecertain embodiments, the motor slowdown signal on path 161 ₂ can beeliminated, or the input on path 161 ₂ can be used for other controlsignals to the motor control circuit.

As mentioned previously, when tissue cutting device 40 is deactivated,inner cannula 76 may come to rest partially disposed within outercannula opening 49. Referring to FIGS. 25-27, three different stoppositions of inner cannula 76 are shown. For ease of viewing, fluidsupply sleeve 302 is not shown. FIG. 27 shows that inner cannula 76 canbe stopped in a position in which a portion of the tissue T is trappedbetween the outer cannula opening 49 and the inner cannula distal end79. Efforts at withdrawing outer cannula 44 from the surgical site mayaccordingly result in tearing of the tissue portion T′ away from thesurrounding tissue base T. Surgeons encountering such trapping wouldtypically be required to re-activate tissue cutting device 40 to releasethe tissue portion T′ from the surrounding tissue base T. To preventsuch tissue trapping from occurring, deactivation of the motor 62 iscontrolled in such a manner that the inner cannula distal end 79 ispositioned remotely from the outer cannula opening 49 when inner cannula76 stops reciprocating. However, in certain methods of use, device 40 isused as an aspiration wand. In those methods, the stop position of innercannula distal end 79 may be adjusted to different locations withinouter cannula opening 49 in order to adjust the level of aspirationsupplied to a region of the anatomy proximate outer cannula opening 49.For example, stop positions may be selected that limit the percent openarea of outer cannula opening 49 to 25%, 50%, or 75% of the total areaof opening 49.

Referring again to FIGS. 23 and 24, controlled deactivation of the motor62 will now be described in detail. When it is desired to deactivatetissue cutting device 40, a motor stop command is provided such as viafoot switch 144 or a panel control 138. In one embodiment, MCU 158 isresponsive to the motor stop command to provide a slowdown signal to thePWM generator via signal path 161 ₂ which slows the action of motor 62.Preferably, the slowdown signal corresponds to a predefined signal leveloperable to drive the motor 62 at a motor speed below a motor speedthreshold level. Since motor 62 is a brushed DC motor, it has arotational resistance or resistive torque associated therewith asdescribed above. In addition, in some cases friction between the innercannula 76 and outer cannula 44 will increase the rotational resistance.Due to this combined rotational resistance, operation of the motor 62will cease very rapidly or nearly instantly if the motor drive signal onsignal path 142 is disabled while driving motor 62 below the motor speedthreshold. Accordingly, when device 40 is used to cut tissue, alignmentof position indicators 176 a or 176 b with sensor 174 preferablycorresponds to a position of the tissue cutting device 40 at which thereis no danger of trapping tissue between inner cannula distal end 79 andthe outer cannula opening 49, and sensor 174 is operable to produce themotor stop identification signal when so aligned with indicator 176 a or176 b.

In one embodiment, MCU 158 is operable to produce a motor stop signal onsignal path 161 ₃ when sensor 174 detects alignment of positionindicators 176 a or 176 b therewith after one passage thereby ofindicator 176 a or 176 b since producing the slowdown signal on signalpath 161 ₂. Allowing one passage of indicator 176 a or 176 b by sensor174 after issuing the slowdown signal ensures that the rotational speedof motor 62 is at or below the motor speed threshold when subsequentlyissuing the motor stop command, regardless of the position of indicator176 a or 176 b relative to sensor 174 when the slowdown command wasissued. After one passage of indicator 176 a or 176 b by sensor 174since issuing the slowdown signal, MCU 158 is responsive to the signalprovided by sensor 174 indicative of alignment of indicator 176 a or 176b therewith, to produce the motor stop signal on signal path 161 ₃. Themotor driver 172 is responsive to the motor stop signal to produce amotor disable signal on signal path 175. Due to the inherent rotationalresistance, motor 62 is responsive to the motor disable signal toimmediately cease operation thereof with indicator 176 a or 176 bsubstantially aligned with sensor 174, and with the inner cannula 76accordingly positioned so as not to trap tissue between inner cannuladistal end 79 and the outer cannula opening 44.

As mentioned above, in one exemplary embodiment, the inner cannula stopposition is user adjustable, such as by adjusting a panel control 138 onconsole 134. In accordance with the embodiment, it is contemplated thatthe stopped rotational position of cam 64, and therefore the innercannula distal end 79, may be instead aligned with a predetermineddifferential distance between the indicator 176 a/176 b and the sensor174. The braking characteristics of the inner cannula 76 and motor 62can be ascertained and the stopping distance determined so that thispredetermined differential distance can be calibrated accordingly.However, in a preferred embodiment, when inner cannula 76 comes to rest,the distal end 79 is located proximally of the outer cannula opening 44by a predetermined distance, as shown in FIG. 26.

A method of using device 40 to perform a tissue cutting procedure willnow be described in the context of a neurosurgical procedure involvingthe cutting of a neurological target tissue. In one example, the targettissue is brain tissue, and in another example the target tissue isspinal tissue, for example, the tissue of an intervertebral disk. Incertain exemplary methods, the tissue specimen being cut is a tumor or alesion.

In accordance with the method, it is first determined whether thecutting operation will be a debulking operation, a fine shavingoperation, or a cutting operation that is somewhere in between adebulking and fine shaving operation. A surgical access path is thencreated to the tissue sample of interest. In one embodiment, thesurgical path is created and/or the target tissue is accessed using an“open” procedure in which the target tissue is open to the atmosphere(e.g., a full open craniotomy). In another embodiment, the surgical pathis created and/or the target tissue is accessed using a “closed”procedure in which the target tissue is sealed from the atmosphere.

At this point, the distal end 79 of inner cannula 76 is locatedproximally of outer cannula opening 49 due to the use of an innercannula stop position control of the type described previously. Themaximum vacuum level to be applied to device 40 is then set using panelcontrols 138. Generally, higher vacuum levels will be used for debulkingprocedures than for fine shaving procedures as higher vacuum levels willtend to draw relatively larger sections of tissue into outer cannulaopening 49. In one embodiment, the panel control 138 is a knob onconsole 134 that is rotated to set the desired maximum vacuum level.

In one arrangement, device 40 is configured to be gripped with a singlehand during a tissue cutting procedure. Thus, the surgeon will grasphandpiece 42 in the fingers of one hand and insert outer cannula 44 to alocation proximate the target tissue. Depending on the hand and thesurgeon's orientation with respect to the target tissue, the surgeon maythen rotate dial 60 to rotate outer cannula 44 about its ownlongitudinal axis and orient outer cannula opening 49 immediatelyadjacent the target tissue. The rotation of outer cannula 44 with dial60 causes inner cannula 76 to rotate such that a fixed rotational orangular relationship is maintained between inner cannula 76 and outercannula 44. Once the opening is in the desired orientation, the motor 62is activated, for example, by beginning to depress pedal 144 from itsfully undepressed (open) position to a second partially depressedposition which causes motor control unit 160 to send a signal to motor62 on signal path 142. Motor 62 may also be activated by a panel control138. The rotation of motor 62 causes cam 64 to rotate, resulting in thereciprocation of cam follower 68 and cam transfer 72. The reciprocationof cam transfer 72 causes cannula transfer 74 to reciprocate, therebyreciprocating inner cannula 76 within outer cannula lumen 110.

Once motor 62 is activated, vacuum is supplied to inner cannula lumen78. In one embodiment, as the pedal 144 is further depressed (beyond theposition at which motor 62 is activated), vacuum generator 153 isactivated. The surgeon then adjusts the degree of depression of the footpedal 144 to obtain the desired level of vacuum by visualizing themovement of the target tissue relative to the outer cannula opening 49.In certain embodiments, the surgeon controls the vacuum level to obtaina desired amount of traction in the tissue surrounding the targettissue. If the surgeon desires to apply the previously set maximumvacuum level, he or she depresses pedal 144 to its fully depressedposition.

If desired, the surgeon may depress and partially release the pedal 144a number of times to manipulate the target tissue in a satisfactorymanner. Vacuum controller 166 is manipulable to adjust the setpoint ofvacuum generator 153 which is manipulable to adjust the inner cannulavacuum level along a continuum of levels below the pre-selected maximumlevel. In one embodiment, the extent of depression of foot pedal 144dictates the vacuum set point supplied to vacuum control unit 166 onsignal path 167, and therefore, the amount of vacuum provided by vacuumunit 168. Vacuum sensor 164 measures the vacuum supplied to tissuecollector 58 and feeds a signal back to main control unit 158 on signalpath 165. The measured vacuum is then compared to the set point appliedto vacuum control unit 166 via foot pedal 144, and the signaltransmitted to vacuum generator 153 is then adjusted to move themeasured vacuum value towards the set point. To obtain a vacuum levelequal to the maximum pre-set level, pedal 144 is completely depressed.Maximum vacuum levels of at least about 0 in Hg. are preferred, andmaximum vacuum levels of at least about 1 in Hg. are more preferred.Maximum vacuum levels of at least about 5 in Hg. are even morepreferred, and maximum vacuum levels of at least about 10 in Hg. arestill more preferred. Maximum vacuum levels of at least about 20 in. Hg.are yet more preferred, and vacuum levels of at least about 29 in. Hg.are most preferred.

Due to the resistance of the tissue drawn into outer cannula opening 49,cutting section 83 pivots about hinge 80 and toward outer cannulaopening 49 as inner cannula 76 travels in the distal direction. Theinner cannula cutting section 83 continues to pivot as it travels in thedistal direction, eventually compressing tissue within outer cannulaopening 49 and severing it. The severed tissue forms a continuum oftissue snippets 112 (FIG. 14) within inner cannula lumen 78. Due to thevacuum applied to tissue collector 58, snippets 112 are aspiratedthrough inner cannula lumen 78 in the proximal direction. Theyeventually exit inner cannula lumen 78 at inner cannula proximal end 77and enter tissue collector 58 (or fluid collection canister 192 if nocollector 58 is provided). Any fluids that are aspirated exit tissuecollector 58 and are trapped in fluid collection canister 192. Thesurgeon preferably severs tissue at a cutting rate of at least about1,000 cuts/minute. Cutting rates of at least about 1,200 cuts/minute aremore preferred, and cutting rates of at least about 1,500 cuts/minuteare even more preferred. Cutting rates of less than about 2,500cuts/minute are preferred. Cutting rates of less than about 2,000 aremore preferred, and cutting rates of less than about 1,800 cuts/minuteare even more preferred.

The surgeon may move device 40 around the target tissue until thedesired degree of cutting has been completed. Motor 62 is thendeactivated, for example, by completely releasing pedal 144 so itreturns to its fully undepressed (open) position. If an inner cannulastop position control is provided, inner cannula 76 preferably comes torest proximally of outer cannula opening 49, as shown in FIG. 26. Outercannula 44 is then removed from the surgical site. Tissue collector 58is then removed from upper housing 52 of handpiece 42, and the collectedtissue samples are either discarded or saved for subsequent analysis.Fluids collected in canister 192 are preferably discarded. If the remotetissue collector of FIG. 21A is used, tissue samples may be removed fromit without removing outer cannula 44 from the surgical site or otherwisedisturbing the surrounding tissue.

As mentioned previously, tissue cutting device 40 includes a deliverysleeve 302 which is selectively disposable about outer cannula 44 (i.e.,the user can install or remove delivery sleeve 302 from outer cannula44). As best seen in FIGS. 28-31, delivery sleeve 302 includes anelongated channel section 304 that comprises an outer cannula channel314 and at least one delivery channel through which fluids or devicesmay pass. In the depicted embodiment, the at least one delivery channelis a fluid or device delivery channel 312. When the delivery sleeve 302is in an uninstalled condition (e.g., FIG. 28), the delivery channel 312may be separate from the outer cannula channel 314 along all or aportion of the length of elongated channel section 304 by a barrierwall, membrane, etc. However, in the example of FIG. 30, the outercannula channel 314 is in fluid communication with the fluid supplychannel 312 along the entire length of elongated channel section 304when the delivery sleeve 302 is in an uninstalled condition. As bestseen in FIG. 30, when delivery sleeve 302 is in an installed condition,outer cannula 44 occupies outer cannula channel 314 and effectivelyseparates outer cannula channel 314 from delivery channel 312.

Referring to FIG. 1, hub 306 is connected to a fluid supply line 308,which is preferably a length of flexible, plastic tubing. Fluid supplyline 308 includes a fluid source connector 310 on its proximal end.Fluid source connector 310 may be any known type of connector suitablefor providing fluid flow. In the embodiment of FIG. 1, fluid sourceconnector 310 is a male luer fitting.

Hub 306 may be connected to elongated channel section 304 in a varietyof ways. One example is depicted in FIG. 29. As shown in the figure,proximal end 317 of elongated channel section 304 is connected to anddisposed in the interior of hub 306. Hub 306 preferably includes acomplementary channel (not separately shown) in which proximal end 317of elongated channel section 304 is interfitted. The connection betweenelongated channel section 304 and hub 306 may be made in a variety ofways, including with adhesives and mechanical fasteners. In addition,elongated channel section 304 may be integrally formed with hub 306 suchas by integrally molding elongated channel section 304 and hub 306 as asingle piece. In the embodiment of FIG. 29, elongated channel section304 and hub 306 are separately formed and then connected with anadhesive.

In one exemplary configuration, hub 306 is generally cylindrical inshape. Hub 306 also includes a proximal opening 322 and a distal opening323. Outer cannula 344 slidably projects through proximal end opening322 and distal end opening 323. However, at distal hub end opening 323,outer cannula 44 projects through elongated channel section 304 ofdelivery sleeve 302. As shown in FIG. 1, in one exemplary configuration,the distal end 47 of outer cannula 44 projects through and away from thedistal end 320 of elongated channel section 340 when delivery sleeve 302is in an installed condition on outer cannula 44. An interior channel(not separately shown) is formed in the interior of hub 306 to retainouter cannula 44. Hub 306 may also include exterior surface featureswhich enhance the user's ability to grip the hub such as when deliverysleeve 302 is being slid along outer cannula 44 to reposition deliverysleeve 302 along the length of outer cannula 44 or to rotationallyorient the sleeve so that the distal end of the delivery sleeve may bealigned as desired by the user. In one example, a plurality oflongitudinally oriented grooves are spaced apart from one another aroundthe circumference of hub 306 and are provided to facilitate gripping. Inanother example, a plurality of protruding axially oriented ridges areprovided and are spaced apart around the circumference of hub 306.

Fluid supply port 316 is provided along the length of hub 306 and isconnected to fluid supply line 308. Fluid supply port 316 may comprisean opening in hub 306 and may also include a projecting connector orflange for securing fluid supply line 308 therein. Interior deliverychannel 318 is provided in hub 306 and is in fluid communication withsupply port 316 and with delivery channel 312 via open proximal end 319in delivery channel 312. Elongated channel section 304 includes a distalend opening 313 in the delivery channel 312 through fluid which may beprovided to the surgical site, typically at or proximate to a targettissue being resected.

Elongated channel section 304 is preferably rigid or semi-rigid and madeof a material that is suitable for use with sterilization techniques,such as ethylene oxide sterilization, Sterrad, autoclaving and gammaradiation sterilization. These include resins and metals. One type ofsuitable polymer material is heat shrinkable tubing. Additional suitableclasses of polymers for forming elongated channel section 304 includegamma-compatible polyimides and polyamides, such as Kapton® polyimidessupplied by DuPont, and Nomex polyamides supplied by DuPont. Polyesterand polyethylene heat shrink tubing are also suitable classes of polymermaterials. One exemplary class of heat shrink tubing is polyethyleneterephthalate (PET) heat shrink tubing supplied by Advanced Polymers,Inc. Suitable materials for forming hub 306 include stainless steel,aluminum, and polymeric materials such as silicone polymers, and naturalor synthetic rubbers.

As shown in FIG. 30, outer cannula channel 314 is partially-cylindricaland defines a partially circular cross-section. Delivery channel 312 mayalso be partially-cylindrical. However, in the example of FIG. 30,delivery channel 312 is generally in the shape of a partial ellipticcylinder (i.e., a cylinder with a partial elliptical cross-section).Inwardly directed ridges 324 and 326 define a transition between outercannula channel 314 and fluid supply channel 312 along the length offluid supply sleeve 302.

As mentioned previously, in one example, elongated channel section 304is formed from heat shrink tubing. In certain embodiments, the heatshrink tubing is provided as a cylindrical length of tubing and is thenmodified to provide a dual channel structure such as the one depicted inFIG. 30. The dual channel structure may be provided by disposing thecylindrical heat shrink tubing around a mandrel having the cross-sectionof elongated channel section 304 which is depicted in FIG. 30 andapplying heat to shrink the cylindrical tubing and conform itscross-section to that of FIG. 30.

In one example, when delivery sleeve 302 is in an installed condition onouter cannula 44, outer cannula 44 may be rotated with respect todelivery sleeve 302. In one illustrative example, the surgeon may griphub 306 with the fingers of one hand to restrain its rotational movementand rotate outer cannula rotation dial 60 with the thumb and/or fingersof the other hand to adjust the circumferential position of outercannula opening 49. While delivery sleeve 302 may be configured torotate with outer cannula 44, in many instances it is preferable tomaintain the circumferential orientation of fluid supply sleeve 302 inorder to prevent delivery supply line 308 from twisting. As shown inFIG. 1, in one preferred orientation, delivery sleeve 302 iscircumferentially oriented such that delivery channel 312 is disposedbetween the longitudinal axis L₁ of handpiece lower housing 50 and outercannula channel 314 in a direction that is substantially perpendicularto handpiece lower housing longitudinal axis L₁. In one example, whereindelivery sleeve 302 is used to deliver a hemostatic agent, it ispreferable to orient fluid supply channel 312 such that it is spacedapart from outer cannula opening 49 in a direction perpendicular to thelower housing longitudinal axis L₁ (see FIG. 31) to prevent theaspiration of the hemostatic agent through outer cannula opening 49.However, other delivery channel 312 orientations may be used dependingon the procedure involved and the type of material or device to bedelivered.

Delivery sleeve 302 may be connected to a fluid source via deliverysupply connector 310. The fluid source may be pressurized orunpressurized. Unpressurized fluids may be elevated to provide thenecessary hydrostatic head to deliver the fluids through fluid supplychannel 312. Referring now of FIGS. 33-38, an alternative embodiment ofa delivery sleeve 402 will now be described. As shown in FIG. 33,delivery sleeve 402 is selectively disposed about outer cannula 44(i.e., the user can install or remove delivery sleeve 402 from outercannula 44) to selectively deliver fluid (such as, for example, ahemostatic agent) to the surgical area. Delivery sleeve 402 includes anelongated channel section 404 that comprises an outer cannula lumen 414and at least one fluid delivery lumen 412. Fluid delivery lumen 412 isconnected to the outer cannula lumen 414, at least partially, alongtheir respective lengths. In one exemplary arrangement, fluid deliverylumen 412 and outer cannula lumen 414 are arranged so as to be orientedin a co-planar manner as seen in FIG. 34.

Delivery sleeve 402 is defined by a distal end 420. Further, outercannula lumen 414 is also defined by a distal end 415 and a proximal end417 (best seen in FIGS. 35 and 36). Fluid delivery lumen 412 is alsodefined by a distal end 413 and a proximal end 419 (best seen in FIGS.35 and 36). As may be seen in FIGS. 33-34, in one exemplary embodiment,distal end 413 of fluid delivery lumen 412 may be slightly angled. Forexample, as shown in FIG. 34, distal end 413 is angled upwardly towardouter cannula lumen 414. In another exemplary embodiment, distal end413′ of fluid delivery lumen 412 is not angled with respect to distalend 415 of outer cannula lumen 414, as seen in FIG. 40, for example.

A proximal end of the delivery sleeve 402 is positioned in and supportedby a hub 406. Details of the hub 406 may be seen in FIGS. 35-38,although it should be noted that for ease of explanation, only a lowersection of hub 406 is illustrated. Hub 406 is defined by a body portion403 that includes a distal face 405 and a proximal face 407. In oneconfiguration, body portion 403 may be formed as mirror image lower andupper sections (lower section visible in FIGS. 34-38) that areconfigured to snap together or are otherwise connected together to formbody portion 403. Body portion 403 includes a first channel 409 and asecond channel 411. First channel 409 extends from distal face 405 to afirst portion 407 a of proximal face 407. First and second channels 409,411 are configured to receive the proximal end of delivery sleeve 402,as best seen in FIGS. 35 and 36. In one exemplary configuration,proximal ends 417 and 419 are fixedly secured within first and secondchannels 409, 411 such that delivery sleeve 402 is integrally connectedto body portion 406. Proximal ends 417 and 419 may be fixed to bodyportion 406 in any suitable member. For example, proximal ends 417 and419 may be glued within first and second channels 409, 411.

In one embodiment, first portion 407 a of proximal face 407 includes amounting portion 410 that is configured to selectively receive a distalend face 59 of upper housing 52 of tissue cutting device 40. A mountingflange 421 may also be provided for selectively receiving a mountingring 422 disposed about a portion of upper housing 52. Further, bodyportion 403 may also include a proximally extending clip member 423. Asmay be seen in FIG. 33, clip member 423 is configured to extend aroundgrasp a portion of mounting ring 422 to provide a quick connect/releasemechanism to secure hub 406 to tissue cutting device 40. However, it isunderstood that other mechanisms for selective attachment of hub 406 totissue cutting device 40 are also contemplated.

In one embodiment, second portion 407 b of proximal face 407 may beconfigured with a connecting portion 425 that is in communication withsecond channel 411. In one exemplary arrangement, connecting portion 425comprises a distal portion 427 and a proximal portion 429. Secondchannel 411 opens into distal portion 427, while proximal portion 429opens into second portion 407 b of proximal face 407. In oneconfiguration, connection portion 425 is configured with an annularretaining lip 431 that extends at least partially between distal andproximal portions 427, 429. In yet another exemplary configuration,annular retaining lip 431 extends continuously around the inner surfaceof connecting portion 425. In one exemplary arrangement, connectingportion 425 is configured to be connected to a valve member 435 to whichsuitable tubing 437 for delivering fluid is attached, as shown in FIG.39. Valve member 435 may be selectively mounted to the connectingportion 425. Alternatively, valve member 435 may be pre-assembled withhub 406.

Valve member 435 may also be provided with an on/off switch 439 toselectively close a fluid line within valve member 435 (and thereforeprevent fluid from flowing through second channel 411 and into fluidlumen 412). In one exemplary arrangement, on/off switch is configured tobe finger operable.

Body portion 406 may also be provided with retaining fingers 433. Asseen in FIG. 33, when hub 403 is installed on tissue cutting device 40,retaining fingers 433 are disposed on either above or below a portion oftissue cutting device 40, along each side of tissue cutting device 40.When installed, fingers 433 serve to frictionally engage either tissuecutting device 40 or, if provided, mounting ring 422 so as torotationally fix hub 403 with tissue cutting device 40. In other words,fingers 433 prevent hub 403 from rotating.

A variety of different fluids may be delivered to a target tissue orproximate to the target tissue. In one example, irrigants such as salineare used to flush and subsequently clear excised tissue and body fluidsat the surgical site. Saline, when elevated in temperature, may alsofunction as a hemostatic agent to facilitate a “clotting cascade” whichultimately leads to the clotting of severed blood vessels in tumors orother tissues at the surgical site. Other hemostatic agents, sealants,and/or tissue adhesives may also be delivered to a surgical site viafluid supply channel 312. Examples include liquid embolic systems suchas Neucrylate, a cyanoacrylate monomer derivative supplied by ValorMedical. Neurcrylate is delivered as a liquid and forms a spongy, solidmaterial upon contacting blood. Another example of a suitable hemostaticagent is supplied by Medafor, Inc. under the name Arista AH AbsorbableHemostat. Arista AH functions as a molecular filter by separating serumfrom cellular constituents. It absorbs water from the blood and forms agel matrix that slows blood flow and serves to enhance clotting.

Fibrin sealants may also be delivered to a surgical site via deliverychannel 312 or fluid delivery lumen 412. One suitable hemostatic matrixsealant is FloSeal®, a fibrin sealant comprising human thrombin which issupplied by Baxter Hyland Immuno. Another suitable sealant is Tisseel, aVH Fibrin Sealant comprising human thrombin, human fibrinogen, andbovine aprotinin. Certain sealants may comprise two or more fluidcomponents that are mixed at or near the site of delivery. In suchcases, the at least one fluid supply channel 312 and/or fluid lumen 412preferably comprises two or more fluid supply channels that contain therespective two or more fluid components which are mixed at open distalend 313 of fluid supply channel 312 or distal end 413 of fluid lumen412. Synthetic sealing agents may also be delivered via delivery channel312 and/or fluid lumen 412. One such example is CoSeal, a hydrogelcomprising 2 polyethylene glycol polymers supplied by Baxter. The 2polymers are preferably delivered via two separate fluid deliverychannels and chemically bond to one another on mixing to form amechanical barrier that slows bleeding. Another suitable synthetic sealis Duraseal, which is supplied by Confluent Surgical. Duraseal comprisesa polyethylene glycol polymer ester solution that is mixed at the pointof delivery with a trilysine amine solution. Thus, delivery sleeve 302and/or delivery sleeve 402 is preferably provided with two fluiddelivery channels to facilitate mixing of the two solutions at the pointof delivery.

As mentioned above, in certain examples, it may be desirable to includetwo or more delivery channels in delivery sleeve 302 and/or 402.However, the two or more delivery channels need not be entirely separatealong the length of sleeve 302 and/or 402. Instead, they may combine toform a single channel mixing zone at a defined distance from distal endopening 313/413. The length of such a mixing zone is preferably selectedto ensure thorough mixing without allowing the fluids to form asolidified mixture prior to discharge from delivery sleeve 302/402.

Tissue adhesive glues are another category of fluids that may bedelivered via delivery sleeve 302/402. Suitable tissue adhesive gluesinclude those formed from formaldehyde or glutaraldehyde-based tissueadhesive glues. One suitable type of glutaraldehye based tissue adhesiveglue is BioGlue® a protein hydrogel comprising bovine serum albumin,glutaraldehyde, and water which is supplied by Cryolife, Inc.

In certain examples, elongated channel section 304/404 is formed with animageable material to facilitate the identification of its positionwithin the patient. In one example, elongated channel section 304/404includes an MRI-imageable material. In another example, elongatedchannel section 304/404 includes a positron emission tomography (PET)imageable material such as a radioactive isotope. Suitable isotopesinclude halogenated sugars such as [¹⁸F]fluorodeoxyglucose and isotopesof amino acids such as [¹¹C]methionine In one example, PET imaging isperformed while fluid supply sleeve 302/402 is inserted in the patientto locate the position of fluid supply sleeve 302/402 (and outer cannula44) within the patient and relative to certain anatomical structures.The radioactive isotope may be incorporated in the elongated channelsection 304/404 in a number of ways. In one example, the radioactiveisotope is added to a molten resin used to form elongated channelsection 304/404 and suspended within the solidified resin. In anotherexample, elongated channel section 304/404 is formed with bores (holes,cavities, channels) and dipped into a solution containing theradioactive isotope. The isotope then wicks into the bores same asabove. It could also have a “rough” surface which would allow theradioactive material to remain in the valleys of the surface, it couldalso have a charged surface that would allow the radioactivematerial/solution to be attracted to and stay on the elongated tube,etc.

Delivery sleeve 302/402 can be used to deliver fluids when tissuecutting device 40 is used in a tissue cutting mode or in an aspirationwand mode. In one example, a tissue removal system comprising tissuecutting device 40 with delivery sleeve 302/402 installed on the outercannula 44 is provided. A fluid source is provided and is connected todelivery connector 310 and/or valve member 435. A valve may be providedbetween the fluid source and delivery connector 310 to allow the surgeonto selectively deliver the fluid to delivery sleeve 302. Alternatively,a valve may be provided between fluid source connector 310 and hub 306.

In yet another embodiment, delivery sleeve 302/402, and moreparticularly fluid delivery channel 312 or fluid cannula 412, may beused to provide selective aspiration. For example, in certaincircumstances, such as with fluid filled abnormalities such as cysts,abscesses, etc., it may be desirable to aspirate to a separatecollection container than the tissue collection chamber of the tissuecutting device 40.

For the embodiment shown in FIGS. 1 and 28-32, the surgeon selectivelypositions delivery sleeve 302 at a desired location along the length ofouter cannula 44. In one example, the surgeon grips hub 306 and advancesor retracts fluid supply sleeve 302 along outer cannula 44 to thedesired location. The outer cannula 44 is then inserted into thepatient's body to a location proximate the target tissue. In theembodiment shown in FIGS. 33-40, hub 406 is slid onto outer cannula 44until distal end face 59 of upper housing 52 is seated within mountingportion 410 of first portion 407 a. Clip member 423 (or other suitableretaining member) is then selectively attached to tissue cutting device40. Further, valve member 435 (and tubing 437) are mounted to connectingportion 425 of second portion 407 b.

Once hubs 306/406 are fluidly connected to the fluid sources, fluid issupplied from the fluid source through delivery supply line 308 (ortubing 437), into hub 306/406, and through delivery supply channel 312and fluid lumen 412. The fluid then exits delivery sleeve 302/402 atdelivery channel open distal ends 313/413 and contacts the target tissueand/or surrounding tissues proximate the target tissue. A vacuum levelmay then be supplied to inner cannula lumen 78 in the manner describedpreviously. Motor 62 may be activated as described previously to causeinner cannula 76 to reciprocate within outer cannula lumen 110 and severtissue received in outer cannula opening 49. Fluid may be supplied viadelivery sleeve 302/402 before, during, and/or after reciprocation ofinner cannula 76 within outer cannula lumen 110. Severed tissue snippetsand/or fluids, including but not limited to the fluids supplied via thedelivery sleeve 302/402, are then aspirated through inner cannula lumen78 and into tissue collector 58 as described previously.

In certain examples, tissue cutting device 40 may be used to cut tissueswith significant quantities of vasculaturized tissues which can generatesignificant bleeding. One such example is a hemangioblastoma. In suchcases, a hemostatic agent or sealant of the type described previouslymay be supplied during or after the tissue cutting procedure to minimizeblood flow.

In another exemplary method, a tissue cutting system comprising tissuecutting device 40 and delivery sleeve 302 is provided, and the system isused in an aspiration mode. In accordance with the example, the surgeonselectively positions the delivery sleeve 302 along the length of outercannula 44 to occlude a portion of outer cannula opening 49 as best seenin FIGS. 31 and 32. The delivery sleeve 302 may be used to occlude adesired percent of the open area of outer cannula opening 49 andtherefore to selectively adjust the aspiration provided at outer cannulaopening for a given vacuum level supplied to inner cannula lumen 78. Forexample, delivery sleeve 302 positions may be selected that limit thepercent open area of outer cannula opening 49 to 25%, 50%, or 75% of thetotal area of opening 49. A vacuum level may then be supplied to innercannula lumen 78 and may draw surrounding tissues into thepartially-occluded outer cannula opening 49. In addition, fluids may beaspirated through outer cannula opening 49, inner cannula lumen 78,tissue collector 58, and collected in fluid collection canister 192(FIG. 21A). With tissue drawn into outer cannula opening 49, motor 62may be activated to sever the received tissue and collect it asdescribed previously. Thus, delivery sleeve 302 effectively allows thesurgeon to manually adjust the degree of aspiration at outer cannulaopening 49, and correspondingly, the size of the tissue samples that arereceived in outer cannula opening 49 and severed by inner cannula 76.Fluid may be supplied at or near the target tissue via fluid supplychannel 312 before, during, and/or after tissue resection. However,delivery sleeve 302 may also be used to adjust the degree of aspirationprovided by tissue cutting device 40 without supplying fluids.

Referring now of FIGS. 41-44, an alternative embodiment of a deliverysleeve 502 will now be described. As discussed above in connection FIGS.33 and 39, delivery sleeve 502 is selectively disposed about outercannula 44 (i.e., the user can install or remove delivery sleeve 502from outer cannula 44) to selectively attach an optical device (such as,for example, a fiber optic bundle) to the surgical area. Delivery sleeve502 includes an elongated channel section similar channel section 404described above. The elongated channel section comprises an outercannula lumen 514 and at least one optical delivery lumen 512. Opticaldelivery lumen 512 is connected to the outer cannula lumen 514, at leastpartially, along their respective lengths. In one exemplary arrangement,optical delivery lumen 512 and outer cannula lumen 514 are arranged soas to be oriented in a co-planar manner similar to that which was shownin FIG. 34. The optical device may be selectively positioned withinoptical delivery lumen 512. More specifically, the optical device may beadjusted along the axial length of optical delivery lumen 512 such thatit may be retracted from or extend past a distal end of optical deliverylumen 512. Further, in one exemplary arrangement, delivery sleeve 502may be selectively rotated about outer cannula 44 such that the angularposition of delivery sleeve 502 may be adjusted by the user.

Outer cannula lumen 514 is defined by a proximal end 517 (best seen inFIGS. 41 and 42). Optical delivery lumen 512 is also defined by aproximal end 519 (best seen in FIG. 42). Proximal end 519 may beslightly angled (as shown in FIG. 42), to provide ease of insertion ofan optical fiber into optical delivery lumen 512. A proximal end of thedelivery sleeve 502 is positioned in and supported by a hub 506. Detailsof the hub 506 may be seen in FIGS. 41-44, although it should be notedthat for ease of explanation, only a lower section of hub 506 isillustrated. Hub 506 is defined by a body portion 503 that includes adistal face 505 and a proximal face 507. In one configuration, bodyportion 503 may be formed as mirror image lower and upper sections(lower section visible in FIGS. 41-44) that are configured to snaptogether or are otherwise connected together to form body portion 503.Body portion 503 includes a first channel 509 and a second channel 511.First channel 509 extends from distal face 505 to a first portion 507 aof proximal face 507. First and second channels 509, 511 are configuredto receive the proximal end of delivery sleeve 502, as best seen inFIGS. 41 and 42. In one exemplary configuration, proximal ends 517 and519 are fixedly secured within first and second channels 509, 511 suchthat delivery sleeve 502 is integrally connected to body portion 506.Proximal ends 517 and 519 may be fixed to body portion 506 in anysuitable member. For example, proximal ends 517 and 519 may be gluedwithin first and second channels 509, 511.

In one embodiment, first portion 507 a of proximal face 507 includes amounting portion 510 that is configured to receive distal end face 59 ofupper housing 52 of tissue cutting device 40. A mounting flange 521 mayalso be provided for receiving a mounting ring 422 (as shown in FIG. 39,for example) disposed about a portion of upper housing 52. Further, bodyportion 503 may also include a proximally extending clip member 523. Asmay be seen in FIG. 33, clip member 523 is configured to extend aroundand grasp a portion of mounting ring 422 to provide a quickconnect/release mechanism to secure hub 506 to tissue cutting device 40.However, it is understood that other mechanisms for selective attachmentof hub 506 to tissue cutting device 40 are also contemplated.

In one embodiment, second portion 507 b of proximal face 507 may beconfigured with a connecting portion 525 that is in communication withsecond channel 511. In one exemplary arrangement connecting portion 525comprises a distal portion 527 and a proximal portion 529. Secondchannel 511 opens into distal portion 527, while proximal portion 529opens into second portion 507 b of proximal face 507. In oneconfiguration, connection portion 525 is configured with an annularretaining lip 531 that extends at least partially between distal andproximal portions 527, 529. In yet another exemplary configuration,annular retaining lip 531 extends continuously around the inner surfaceof connecting portion 525. In one exemplary arrangement, connectingportion 525 is configured to be funnel shaped such that connectingportion 525 is self-directing to deliver optical fibers, or the like,thereby providing ease of insertion. Optical fibers or a probe membermay be selectively mounted to the connecting portion 525. Alternatively,optical fibers or a probe member may be pre-assembled with hub 503.

Body portion 506 may also be provided with retaining fingers 533. Asseen in FIG. 33, when hub 503 is installed on tissue cutting device 40,retaining fingers 533 are disposed on either above or below a portion oftissue cutting device 40, along each side of tissue cutting device 40.When installed, fingers 533 serve to frictionally engage either tissuecutting device 40 or, if provided, mounting ring 422 so as torotationally fix hub 503 with tissue cutting device 40. In other words,fingers 533 prevent hub 503 from rotating.

Optical delivery lumen 512 allows for effectively coupling tissuecutting device 40 to another separate device to provide integratedvisualization and to assist in differentiation of critical structures,healthy tissue and diseased tissue. More specifically, optical deliverylumen 512 is coupled with another separate device to deliver, forexample, a fiber optic bundle for the transmission and reception ofreflected light to a remote sensor, filtered light to illuminateinteraction of dye with tissue or an ultrasound probe or other devices.

In one exemplary embodiment, a fiber optic bundle may be positionedwithin second channel 511 and delivered into the optical delivery lumen512 of the delivery sleeve 502. In one exemplary arrangement, the fiberoptic bundle may be used for photocoagulation of blood. Morespecifically, the fiber optic is used as a laser to produce light in asuitable wavelength that may be selectively absorbed by hemoglobin, tocoagulate blood or ablate blood vessels.

In another exemplary embodiment, the fiber optic bundle may be used inconnection with a tissue-soldering technique to repair a dural defect.In this configuration, the fiber optic bundle may be used to deliverlaser light to weld a substrate directly with a tissue covering (eithernatural or synthetic) or with the use of a soldering fluid, both ofwhich creates a water-tight seal and provides for more effectivehealing. Indeed, the tissue-soldering technique may be used to create awater-tight seal to retain cerebrospinal fluid within the dura. Inanother embodiment, the tissue-soldering technique may be employed toweld a tissue vessel (i.e., a natural channel within the body thatcommunicates tissue or fluid) so as to preserve functionality of thevessel or vessel patency.

In yet another exemplary embodiment, the fiber optic bundle may bedelivered through the delivery sleeve 402 to deliver certain wavelengthsof light for various applications in connection with the tissue cuttingdevice 40. For example, the fiber optic bundle may be utilized forphotodynamic therapy. More specifically, in one embodiment, first apredetermined chemical composition (i.e., a dye) is delivered to thetarget tissue. To activate the chemical composition, a predeterminedwavelength of light is delivered by the fiber optic bundle throughoptical delivery lumen 412. The activation of the chemical compositioncan perform a number of desired results. For example, In one exemplaryarrangement, the predetermined chemical composition selected bonds toproteins from diseased cells. Accordingly, specific wavelengths orcolors of light are delivered by the fiber optic bundle, therebyilluminating the diseased tissue (by virtue of the bonding between thechemical composition and the proteins). With this illumination, tissuecutting device 40 may be more efficiently and safely used to resectdiseased or abnormal tissue. In other embodiments, the predeterminedchemical composition may be used in connection with selected wavelengthsof light to activate a therapeutic reaction.

In another exemplary embodiment, delivery sleeve 402 may used withspectroscopy. More specifically, light may be delivered through theoptical lumen 412 and reflected proximally from the surgical field orthe area of interest. The fiber optic bundle or light probe isoperatively connected to a console such that the reflected light isdelivered to the console. A sensor in the console (i.e., the sensor isremotely located from the point of detection receives the reflectedlight to trigger a signal to the user based on predetermined parameters.In other words, the natural florescence of the tissue is then reflectedback to the console to inform the user whether or not the tissue isdiseased or healthy. Because the delivery sleeve 402 is operativelyconnected to the tissue cutting device 40, use of the spectroscopypermits the user to obtain information about the tissue adjacent to thecutting element such that diseased tissue may be excised more quicklyand effectively and healthy tissue is preserved.

Similarly, in yet another exemplary embodiment, the use of opticalcoherence tomography (“OCT”) may be used. More specifically, a fiberoptic bundle may be operatively connected to a console that employs alow-coherence-interfermoetry to produce a two-dimensional image fromtissue structures. Because the delivery sleeve 402 is operativelyconnected to the tissue cutting device 40, use of OCT permits the userto obtain information about the tissue adjacent to the cutting elementsuch that diseased tissue may be excised more quickly and effectivelyand healthy tissue is preserved.

In yet another exemplary arrangement, an intravascular ultrasound devicemay be delivered through delivery sleeve 402 (and more specifically,optical lumen 412). The ultrasound device is configured to permitviewing of vessels that are positioned so as to be adjacent to thestructure that is being resected or (those imbedded therein). Theultrasound device provides visualization of blood flow in a region ofinterest and acts as a doppler to determine tissue characteristics. Forexample, in one instance, the ultrasound device may be used to determineif there is fluid running through nearby vessels that are notnecessarily visible. In such a configuration, sound is beamed into anarea of interest. The sound reflects off of a moving target, such asblood passing through a vessel, and the pitch of the sound wave changesmay change in accordance with the Doppler Effect. The ultrasound devicecan be configured to detect subtle pitch changes and record themvisually, creating an image showing where blood is flowing. Theultrasound device may, for example, be used to map out the location ofcritical structures adjacent suspected tumors, thereby providing aphysician the ability to evaluate treatment options and to avoiddamaging such structures when tissue cutting device 40 is beingutilized.

While described in the context of an intravascular ultrasound device, itis also understood a non-ultrasonic/imaging Doppler probe may also beused as described above. More specifically, a Doppler probe thatutilizes an amplifier operatively attached to a microphone to audiblyindicate blood flow may be provided. In one exemplary configuration, theprobe emits an audible pulsed signal, which varies when the probe isplaced upon (or near) a vessel within which is there is flow. Thefrequency (i.e., pitch) of the signal is proportional to the bloodvelocity within the vessel. Accordingly, as set forth in the descriptionabove, positioning of the Doppler probe through the delivery sleeve 402assists in identifying and accessing critical blood vessels and otherstructures, adjacent the tissue cutting device 40.

In another instance, the ultrasound may be used to view extent of atumor for resection. In yet another instance, the ultrasound device mayalso be used within the delivery sleeve 402 (with the tissue cuttingdevice 40) for providing visualization beyond a tumor to assist the userin ascertaining the fibrotic nature of the tissue, therebydistinguishing between healthy tissue and diseased tissue, in real-timeand in conjunction with resection. In other words, the ultrasound devicemay be provided with tissue characteristic interpretation, (i.e.,elastography). This configuration provides for parallel insertion andutilization of both an ultrasound device and tissue cutting device 40,thereby minimizing multiple introduction and removal operations ratherthan prior art systems which required serial insertion and removal,thereby extending the procedure and potential loss of focus for thesurgeon. Moreover, use of an ultrasound probe through delivery sleeve402 in connection with a tissue cutting device 40 is especiallyadvantageous in minimally invasive neurosurgical procedures in thatspace is very limited. Accordingly, traditional large bore ultrasoundprobes are undesirable.

In another exemplary embodiment a monopolar or bipolar device/probe maybe used in conjunction with and placed down the delivery sleeve 402 toassist in the coagulation of blood at the surgical site. The monopolaror bipolar device/probe may be attached to a cautery generator andthereby provide the user with simultaneous tissue cutting and bloodcoagulation of severed blood vessels.

It will be appreciated that the tissue cutting devices and methodsdescribed herein have broad applications. The foregoing embodiments werechosen and described in order to illustrate principles of the methodsand apparatuses as well as some practical applications. The precedingdescription enables others skilled in the art to utilize methods andapparatuses in various embodiments and with various modifications as aresuited to the particular use contemplated. In accordance with theprovisions of the patent statutes, the principles and modes of operationof this invention have been explained and illustrated in exemplaryembodiments.

It is intended that the scope of the present methods and apparatuses bedefined by the following claims. However, it must be understood thatthis invention may be practiced otherwise than is specifically explainedand illustrated without departing from its spirit or scope. It should beunderstood by those skilled in the art that various alternatives to theembodiments described herein may be employed in practicing the claimswithout departing from the spirit and scope as defined in the followingclaims. The scope of the invention should be determined, not withreference to the above description, but should instead be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled. It is anticipated andintended that future developments will occur in the arts discussedherein, and that the disclosed systems and methods will be incorporatedinto such future examples. Furthermore, all terms used in the claims areintended to be given their broadest reasonable constructions and theirordinary meanings as understood by those skilled in the art unless anexplicit indication to the contrary is made herein. In particular, useof the singular articles such as “a,” “the,” “said,” etc. should be readto recite one or more of the indicated elements unless a claim recitesan explicit limitation to the contrary. It is intended that thefollowing claims define the scope of the invention and that the methodand apparatus within the scope of these claims and their equivalents becovered thereby. In sum, it should be understood that the invention iscapable of modification and variation and is limited only by thefollowing claims.

1. A tissue removal system, comprising: a handpiece; an outer cannulahaving an outer cannula lumen, a proximal end, a distal end, and anouter cannula opening adjacent the distal end, wherein the openingdefines a cutting edge for severing tissue; an inner cannula disposed inthe outer cannula lumen and reciprocable within the outer cannula lumen,the inner cannula having an inner cannula lumen, a proximal end, an opendistal end and a cutting edge at the distal end; and a delivery sleevedisposed about the outer cannula, wherein the delivery sleeve comprisesan outer cannula channel and at least one delivery channel.
 2. Thetissue removal system of claim 1, wherein when the delivery sleeve is inan uninstalled condition, the at least one delivery channel is separatedfrom the outer cannula channel along the length of the delivery sleeve.3. The tissue removal system of claim 1, wherein when the deliverysleeve is in an uninstalled condition, the at least one delivery channelis in fluid communication with the outer cannula channel along thelength of the delivery sleeve.
 4. The tissue removal system of claim 1,wherein when the delivery sleeve is in an uninstalled condition the atleast one delivery channel is in communication with the outer cannulachannel along the length of the outer cannula channel, and when thedelivery sleeve is in an installed condition on the outer cannula, theouter cannula separates the at least one delivery channel from the outercannula channel.
 5. The tissue removal system of claim 1, wherein thedelivery sleeve is selectively positionable along the length of theouter cannula.
 6. The tissue removal system of claim 1, wherein theouter cannula is rotatable with respect to the delivery sleeve and thehandpiece.
 7. The tissue removal system of claim 6, wherein the rotationof the outer cannula causes the inner cannula to rotate with respect tothe handpiece while maintaining a fixed circumferential relationshipbetween the inner cannula and the outer cannula.
 8. The tissue removalsystem of claim 1, wherein the delivery sleeve is at least partiallyconstructed of an imageable material.
 9. The tissue removal system ofclaim 1, wherein at least a portion of the delivery sleeve is visibleunder positron emission tomography.
 10. The tissue removal system ofclaim 1, wherein the delivery sleeve comprises a hub at a proximal endof the delivery sleeve, and the outer cannula projects through theproximal end of the delivery sleeve when the delivery sleeve is mountedto the tissue cutting device.
 11. The tissue removal system of claim 1,further comprising a source of irrigant in fluid communication with theat least one delivery channel.
 12. The tissue removal system of claim 1,further comprising a source of a hemostatic agent in communication withthe at least one delivery channel.
 13. The tissue removal system ofclaim 1, further comprising a source of a tissue sealing agent in fluidcommunication with the at least one delivery channel.
 14. The tissueremoval system of claim 1, further comprising an optical devicepositioned in the at least one delivery channel.
 15. The tissue removalsystem of claim 14, wherein the optical device is one of a fiber opticbundle and an ultrasound probe.
 16. The tissue removal system of claim1, further comprising a Doppler probe positioned in the at least onedelivery channel, wherein the Doppler probe is configured to operativelyconnect to an amplifier and a microphone to provide an audibleindication of blood flow.
 17. The tissue removal system of claim 1,further comprising a cautery device positioned in the at least onedelivery channel.
 18. The tissue removal system of claim 17, wherein thecautery device is one of a monopolar or bipolar probe.
 19. The tissueremoval system of claim 1, further comprising a hub which includes afirst channel and a second channel disposed therein, wherein the outercannula channel and the delivery supply channel being fluidly connectedto the first and second channel, respectively.
 20. The tissue removalsystem of claim 19, wherein the second channel is defined by distal andproximal openings, and where in the proximal opening is configured to bepositioned adjacent a portion of the tissue cutting device when the hubis connected to the tissue cutting device.
 21. The tissue removal systemof claim 20, wherein the proximal opening of the second channel furthercomprises a connecting portion.
 22. The tissue removal system of claim21, wherein the connecting portion is configured to receive a valvemember to fluidly connect the delivery channel to a fluid supply source.23. The tissue removal system of claim 22, wherein the valve member isselectively connected to the connecting portion.
 24. The tissue removalsystem of claim 22, wherein the connecting portion is configured toreceive one of an optical device and probe member.
 25. The tissueremoval system of claim 19, wherein the first channel is defined bydistal and proximal openings, and wherein the proximal opening isconfigured to selectively mate with a portion of the tissue cuttingdevice.
 26. The tissue removal system of claim 19, wherein the hubfurther includes a retaining member that may selectively connect to aportion of the tissue cutting device so as to fixedly secure the hub tothe tissue cutting device in a rotationally fixed manner.
 27. A methodfor performing a surgical procedure, comprising: providing a tissueremoval system, the tissue removal system comprising: a handpiece, anouter cannula having an outer cannula lumen, a proximal end, a distalend, and an outer cannula opening adjacent the distal end, wherein theopening defines a cutting edge for severing tissue; and an inner cannuladisposed in the outer cannula lumen and reciprocable within the outercannula lumen, the inner cannula having an inner cannula lumen, aproximal end, an open distal end, and a cutting edge at the distal end;and a delivery sleeve disposed about the outer cannula and comprising anouter cannula channel and at least one delivery channel; inserting theouter cannula into a patient proximate a target tissue with the deliverysleeve disposed thereon; supplying one of a fluid or a device throughthe at least one delivery channel and to the target tissue or an areaadjacent the target tissue; reciprocating the inner cannula within theouter cannula lumen between a proximal position and a distal position,such that when the inner cannula is in the proximal position, the targettissue is received in the outer cannula opening, and when the innercannula is in the distal position, the cutting edge severs the targettissue that is received in the outer cannula opening from surroundingtissue; and aspirating the severed samples through the inner cannulalumen.
 28. The method of claim 27, further comprising selectivelypositioning the delivery sleeve along the length of the outer cannula tocover a selected portion of the outer cannula opening.
 29. The method ofclaim 27, wherein the device is disposed in the at least one deliverychannel is an optical device, wherein the optical device is activated toprovide photocoagulation.
 30. The method of claim 27, wherein the devicedisposed in the at least one delivery channel is an optical device,wherein the optical device is activated to weld a substrate with atissue covering.
 31. The method of claim 27, further comprisingdelivering a chemical composition to the target tissue and wherein thedevice is disposed in the at least one delivery channel is an opticaldevice that is configured to deliver a predetermined wavelength of lightto a target tissue, wherein the optical device is activated to deliverlight to the target tissue such that said light causes a chemicalreaction with the chemical composition.
 32. The method of claim 31,wherein the light causes the chemical composition to fluoresce.
 33. Themethod of claim 31, wherein the light activates a therapeutic reaction.34. The method of claim 27, wherein the device disposed in the at leastone delivery channel is an ultrasound device, and wherein the ultrasounddevice is activated to indicate the presence of vessels positionedadjacent the target tissue.
 35. The method of claim 27, wherein thedevice is a fiber optic bundle and optical coherence tomography isemployed image the physiological function of tissue.
 36. The method ofclaim 27, wherein the device disposed in the at least one deliverychannel is a cautery device, and wherein the cautery device is activatedto provide coagulation at the target site.
 37. A method for performing asurgical procedure, comprising: providing a tissue removal system, thetissue removal system comprising: a handpiece, an outer cannula havingan outer cannula lumen, a proximal end, a distal end, and an outercannula opening adjacent the distal end, wherein the opening defines acutting edge for severing tissue, and an inner cannula disposed in theouter cannula lumen and reciprocable within the outer cannula lumen, theinner cannula having an inner cannula lumen, a proximal end, an opendistal end, and a cutting edge disposed at the distal end, a deliverysleeve comprising an outer cannula channel and at least one deliverychannel; selectively positioning the delivery sleeve along the length ofthe outer cannula to cover a selected portion of the outer cannulaopening; inserting the outer cannula into a patient proximate a targettissue; and generating a vacuum level in the inner cannula lumen withoutreciprocating the inner cannula within the outer cannula lumen while thedelivery sleeve is located at the selected position along the length ofthe outer cannula.
 38. The method of claim 37, further comprisingdrawing the target tissue into the outer cannula opening while thedelivery sleeve is located at the selected position along the length ofthe outer cannula.
 39. The method of claim 37, further comprisingsupplying a fluid through the at least one delivery channel to thetarget tissue or an area proximate the target tissue.
 40. The method ofclaim 37, wherein the fluid comprises one of an irrigant and ahemostatic agent.
 41. The method of claim 37, wherein the deliverysleeve is at least partially constructed of an imageable material, andthe method further comprises imaging the delivery sleeve.
 42. The methodof claim 37, further comprising operatively connecting a vacuum sourceto the delivery channel.
 43. The method of claim 42, wherein the vacuumsource is operatively connected to an aspiration wand that is insertedwithin the delivery sleeve.
 44. The method of claim 37, furthercomprising inserting an optical device into the delivery sleeve.
 45. Themethod of claim 44, further comprising activating the optical device tophotocoagulate selected tissue.
 46. The method of claim 44, furthercomprising activating the optical device to weld tissue at the targettissue.
 47. The method of claim 44, further comprising delivering achemical composition to the target site and activating the chemicalcomposition by delivering light from the optical device.
 48. The methodof claim 44, wherein the optical device utilizes optical coherencetomography and images the physiological function of tissue.
 49. Themethod of claim 37, wherein a vascular detecting device is deliveredthrough the delivery sleeve to detect blood flow in vessels adjacent tothe tissue cutting device.
 50. The method of claim 49, wherein theintravascular device is a Doppler device.